It is not easy to give a simple guide to refuting atheism, simply because the philosophical belief can vary so much between individuals who all identify as atheists. It will be necessary for the Catholic apologist to identify the reasons why the person is an atheist, and then to address those specific issues. As pointed out elsewhere, it is necessary to determine what the person's real reasons are, rather than that he or she says they are.
Who is this God fellow anyway?
Atheists deny the existence of “gods” - but that necessarily includes a definition of what “god” means. Few atheists realize this logical necessity, and it is up to the apologist to point this out. The word “god” is just a label, and without a definition the atheist doesn't actually mean anything.
The apologist should ask the atheist, “Tell me about the god you don't believe in.” Although this might seem totally illogical and impossible, the atheist will usually be able to give some characteristics of the being he does not believe in. These characteristics are normally a simplistic version of the Christian God – so the atheist denied-god is omnipotent, omniscient, omnipresent, all-loving and so forth.
However, very few atheists have a picture of their denied-god which is, in fact, completely in-line with the Catholic definition of God. Atheists may confuse omnipresence with pantheism, or all-loving with being tolerant of evil (or, even, use the infamous “problem of evil” argument). In short, the atheist is rejecting a god which the Catholic apologist doesn't believe in either!
Technically speaking, Catholics are pagan-atheists, and Hindu-atheists, and New Age-atheists – we deny the existence of these gods! Arguably, we are also Moslem-, Jewish- and perhaps even Protestant-atheists too.
The self-identified “atheist” will deny a particular sort of god – it will be necessary to find out what that god is like and then demonstrate (most likely) that that god is not the real God whom Catholics worship. The atheist can retain his cherished beliefs that a particular being cannot exists because they are not actually incompatible with worshiping the real God.
Lack of direct experience of God
If the person is an atheist because he or she has never had a direct experience of God, then all the Catholic apologist can do is pray and ask the person to pray. It is very difficult (some would say practically impossible) to argue someone to a belief in God through pure logical means – it requires a great intellect (on the part of the apologist and the atheist) and a very solid grounding in philosophy. Saint Thomas Aquinas came up with a number of very good arguments for the existence of God (and also the existence of the human soul) in his Summa Theologica, but these arguments themselves are very complicated and rely on foundational philosophical understanding which is simply beyond or not possessed by most people. Although many atheists claim to be highly educated and clever, this is often simply not the case.
Fortunately, God does not just want those who are intelligent enough to know about Him – He wishes for everyone to come to know and love Him. Most people have an experience of God through prayer – this is the normal method of communicating with God. If the person is an atheist just because he or she has never had any direct experience of God (remember, atheists may not be entirely honest about why they are atheists) then the apologist should ask the person to pray – in their own words, as humbly and genuinely as they can manage.
At that stage, the next phase of apologetics is out of the apologist's hands – and is firmly in God's! All the apologist can do is encourage the person to pray and – if they refuse or do not treat the exercise seriously, or have excessive cynicism about it – tell the person that he or she is being intellectually dishonest, and that there are clearly other – emotional reasons – why he or she is an atheist.
Religion hampers science or leads to violence
Many atheists use these arguments, but these arguments are logically flawed, and the apologist should be able to demonstrate this via the use of logic. In order for the argument that God is not real because religion hampers scientific progress / causes violence to be true, the following two points must be true;
Religion actually is a source of violence or hampers scientific progress
The fact that religion causes violence or hampers scientific progress means that it is untrue.
The second point is a logical jump – just because something causes problems does not mean it does not exist, nor does it mean that its claims are not true. It may mean that a person does not want it to be true, but that is not the same thing at all. From a logical perspective, one point does not lead to the other – there are plenty of things which cause violence (human greed etc.) which clearly exist.
In addition, religion when considered as a single phenomena doesn't cause violence or hamper scientific progress – there are certain religions which do this. A Catholic apologist's duty is to prove the validity of Catholicism – not to defend the entire notion of religion or every single religion in the world. The fact that certain religions have hampered scientific progress and / or caused violence and suffering can actually work to the apologist's advantage; in that Catholicism hasn't (when the historical evidence is examined dispassionately and accurately) and therefore is seen as being “better” than other religions.
The Problem of Evil
This is a predominant theme from atheists – it is exceptionally common and virtually every self-proclaimed atheist uses it in one form or another. It is, however, easily refuted and is – without wishing to sound too dismissive – really Basic Philosophy & Theology 101.
The argument runs as follows; if God is all powerful then He could prevent evil from happening. If God were all-loving, He would want to prevent evil from happening. Evil exists. Therefore, God is either not all-powerful or not all-loving. In either case, He is not worth worshiping (alternatively, God as defined by the Catholic Church does not exist, so I do not worship Him specifically).
Refuting this argument depends on refuting the premises and also refuting the logical structure which forms the conclusion from the premises – both are flawed.
Firstly, God is all-powerful. God could eliminate evil from the world. This is true and accurate.
Secondly, God is “all-loving” or infinitely compassionate. This is true, but there is an implicit third premise in this argument – that infinitely compassionate means that He would wish to prevent “evil” acts and is prepared to take the necessary steps to do so.
Thirdly, the term “evil” is never defined in this argument – what is evil? Asking the atheist will not get a clear answer – given the fact that the only clear definition is “that which is against God” and the atheist denies the existence of God. The atheist will probably give examples of evil – the Holocaust, child rape, murder, war, starvation. All of these things are certainly unpleasant, and many of them are actively evil (some of these things are simply the natural results of evil, selfish actions, and others – like hurricanes and floods – are just natural disasters).
The unspoken premise in this argument is that an all-loving God will intervene to prevent what the atheist defines as unpleasant. This is a key issue – if God interfered prevented everything that was genuinely evil (i.e. what He saw as evil) then no-one would be able to deny His existence, no-one would be able to have premarital sex, no-one would be able to advocate or have an abortion and so forth.
This would result in the complete subjugation of free-will. This is a necessarily logical step – God cannot prevent evil without removing free-will from people (and removing it not just to a degree of coercion – i.e. “Do as I say or you will suffer” - but rather totally removing it so that humanity has no free-will whatsoever and cannot choose to do anything.)
If there is no free-will and humanity cannot choose evil, then humanity cannot choose good either. A rock has no free-will; it is not a moral thing, but neither is it amoral. It simply exists.
So, what does it mean for God to be all-loving? It means that He wants us to choose Him and choose the good. He wants us to reject evil. God's highest good is the correct exercise of free-will to choose Him. He sees death and suffering as, while very unpleasant for humanity, not evil in and of themselves. Death and suffering are often the results of evil actions, but they are not evil themselves.
God is both infinitely loving and infinitely just; in His love He gives everyone the chance to know Him and respond to Him, the chance to choose good. A person who has chosen God and who is killed by an evil man is in a better position than the evil man; he is going to Heaven. God is interested in allowing humanity to choose Him, not in trampling over their wills and turning them into inert objects who have no ability to choose good or evil.
A similar argument to the problem of evil is the idea that an infinitely loving God would never send people to Hell – this is basically the universalist heresy, but with the additional element that God Himself is denied, rather than just the existence of Hell.
A number of atheists will simply ask “If there is a God, why is there so much evil in the world?” A short and snappy answer (which is also very accurate) is “If there is no God, why is there so much good? Why do we even have the idea of good if there is no source for it?”
Individual scientific / historical / social / moral beliefs “prove” that religion is false
There are wide variety of specific belief systems (such as evolution, the notion that homosexuality is okay, the belief that the Church has been responsible for countless deaths) that atheists bring up as “evidence” that there is no god. Addressing these issues – although different in the details – involves basically the same tactic.
Firstly, determine if the belief being advanced is, in fact, true. Is the theory of evolution being advanced accurate, or are there holes in it? Is homosexuality actually moral from a purely secular standpoint, or does it lead to problems and issues which – even when God is taken out of the frame – are disadvantageous to society? If the initial belief isn't accurate, then the whole argument falls apart.
Secondly, and most importantly, does this belief mean that religion isn't true, or does it just mean that the person would find it easier and more appealing if it were not? If a person condemns the Church for forbidding the use of condoms, is that actually proof that God does not exist? Or is it simply proof that the Church (and God) have a different morality to the atheist? Disagreeing with God does not necessarily mean that God does not exist – it means that either you or God are wrong. When this point is reached, it will be necessary to show that the Church's moral positions are – in fact - valid.
The Church contains corrupt individuals and therefore God can't exist
There are two ways of refuting this argument – the first is by pure logic. Merely because corrupt people follow a religion does not mean that the religion is a sham! That is a total logical disconnect. It may be that an individual atheist does not wish to belong to a group which contains such members, but that does not prove that God does not exist. This is the argument of infallibility verses impeccability applied to the Church as a whole.
The second method is by simple example; there are many atheists who have killed people (the Chinese government, for example) – does this mean atheism isn't real? Are Martin Luther King's ideals untrue because he was an adulterer? Are the values of the Founding Fathers wrong because some of them kept slaves? Or are these people just hypocrites?
The truth of a position is not determined by the morality of those who profess to believe it. If a doctor who says that people must lose weight for their health and then dies weighing 350lbs of a heart attack, that does not mean his science was wrong – it means that he just didn't practice what he preached!
The Apologist Strikes Back!
The above examples are all reactive not proactive. The apologist reacts to objections raised by the atheist. However, this should not be the only tactic the Catholic apologist has. Below are a number of active methods of refuting atheism – asking questions and raising objections to that belief!
Humanity's tendency towards depravity
This is an excellent argument to use against evolutionists – not against evolution itself, but rather against atheism.
Most atheists, if asked, will agree that humanity is not morally perfect – there is evil and depravity in human nature. Regardless of what source they ascribe this to (many will ascribe it to “religious men trying to control people!”) the fact remains that it has to have an ultimate source which is external to human consciousness. While people have invented religions to control people and take their money, where did the idea that this could be done come from? Human depravity is not an advantageous trait – it damages the group (because it causes one individual to desire more resources and to hurt others) and is therefore not a beneficial survival trait. It in fact confers no survival advantage to be selfish in terms of resources for a co-operative creature like humanity (although for a lone hunter – like a cat – this would be advantageous.) Most evolutionists think that humanity is genetically predisposed towards a communal living and hunting pattern.
Most theories of evolution maintain that a non-desirable survival trait will rapidly be weeded out of the gene pool – how does this trait (which is not desirable given humanity's nature as a pack animal) survive?
The only logical answer is that either i) it is external to evolution and genetics (and is therefore attributable to what? The Church tells us that the Fall is responsible) or ii) evolution is flawed (and if evolution is flawed, what made life?)
This is an appealing argument to use, but be warned that a number of atheists will either deny humanity's depravity, or will state that it is – in fact – a valid survival mechanism (despite all evidence to the contrary!)
Pascal's Wager is truly effective only against agnostics, although it will work on a number of atheists who haven't thought their position through. In brief, Pascal's Wager states that it is better to believe in God than not because the benefit of believing is potentially infinite (Heaven) and the downside of not believing (Hell) is potentially infinite. The actual act of believing requires only a finite expenditure of energy (as we are finite creatures) therefore it is always worth believing and never worth not believing.
Pascal's Wager sounds exceptionally appealing, but clever people may notice that there is a flaw in it. The wager speaks of belief and it is impossible to act belief through an act of will. What it is possible to do is behave in a certain manner. The hope of Pascal's Wager rests on the notion that God will judge deeds rather than just beliefs. Fortunately, this is the correct teaching and is supported by Catholic theology!
Pascal's Wager does not work very well on died-in-the-wool atheists – but it is very effective on genuine agnostics. Agnostics are not sure if there is a god, but generally speaking act as if they are very sure there is not! Pascal's Wager can be used to suggest to them that – if they are genuinely not sure (as opposed to tied to atheism because of its emotional appeal) – then it is always better to act in a Christian manner. Once someone is praying and conforming their morality to the Christian ideal they are far more likely to actually become a Christian.
Be honest with the atheist
This is perhaps the hardest of all the proactive tactics – be honest with the atheist. You should tell him or her why you think he or she is an atheist; address the emotional appeal of atheism right at the heart. Tell the atheist that he or she is afraid of having to change, of ridicule, of having to waste Sunday mornings. Very often, an atheist will say something like, “So, you think I am going to Hell because I am in a homosexual relationship?” - the primary reason he does not believe is because he would have to change his lifestyle.
The apologist should always be ready to “call out” an atheist – to tell him or her the real reason why he or she rejects God. Very often, this will end the conversation – no-one likes to be called a liar or a coward (which is what this basically is). But the fact remains that unless the real reasons for atheism are addressed they will never be overcome.
Very often, an atheist will be a “fundamentalist atheist” - which means someone who, when presented with any evidence which challenges the position “there is no God”, immediately says that the evidence is flawed, or who says there must be some other explanation. Or, people may be so attached to their lifestyles or so poisoned against religion, for whatever reason, that intellectual arguments will have no effect. With people such as this, apologetics is – sadly – a complete waste of time.
At this stage, the responsibility of a Catholic apologist is twofold;
To pray for the person – the apologist might not be able to get through to the person, but God certainly can!
To ensure that – by using these apologetics techniques against the people the atheist talks to – he or she does not have free rein to spread his or her falsehoods. Apologetics may not be able to convince the atheist to become a Christian, but it might be able to stop Christians from becoming atheists!