Recently, I had a conversation with a friend concerning epistemology (how we come to know certain ideas to be true) and religious propositional claims. My friend asked me how I could be so confident that the evidence supports Christianity when I have not investigated every other religion to find out whether they have any evidence going for them.
This is a common talking-point that I encounter in discussions with atheists. “Have you read the Qur’an?” I am frequently asked. In the case of the Qur’an, I can claim to have read it and I have in fact studied Islam in significant depth. But I have not taken the time to study every religion in comparable detail. Does that mean I cannot conclude Christianity to be true and all other religions to be false? Of course not. By the very nature of concluding that the propositional claims of Christianity are true, one is de facto excluding other possibilities. If, for example, one concludes based on the evidence that Jesus really claimed to be divine (as I argue here), one has excluded as an option all religions that insist that Jesus did not claim to be God (such as Islam). Likewise, if one concludes based on the evidence that the Universe had a definite beginning in the finite past, one has excluded as an option all religions that assert that the Universe is eternal in the past (i.e. pantheistic religions).
It is curious that such reasoning is employed in discussions about religious questions when we rarely use such methodology in any other realm of inquiry. A homicide detective does not need to investigate every single individual in the city before he can conclude that a particular suspect committed the crime. Investigators of John F. Kennedy’s assassination did not need to investigate all of Kennedy’s contemporaries as potential suspects before they could conclude that his assassination was carried out by Lee Harvey Oswald.
One does not need to weigh up the arguments pro and con for every single possible alternative that is out there in order to conclude that a certain hypothesis best explains the available data. When multiple independent lines of evidence converge on a single given hypothesis, other possibilities are by nature excluded and it becomes unnecessary to investigate every conceivable candidate hypothesis before one can reach a proper judgment. Of course, one should always be open to the possibility that one’s judgment is mistaken and be prepared to revise conclusions should new information come to light. But one certainly does not need to investigate the tens of thousands of competing religious propositional claims that are out there in order to conclude that Christianity makes sense of the pertinent available data. Moreover, the claim that one has to investigate every religious proposition in order to assert any religious position backfires on the atheist, for it renders it impossible to draw any religious conclusions — including atheism.
Nobody has the time or resources to invest in studying every religion that has ever been proposed. Although I would encourage people to, at the very least, be acquainted with the three major Abrahamic faiths (Christianity, Islam and Judaism — the only theistic religions to teach creation ex nihilo, a claim consistent with modern cosmology), for one to be rationally justified in affirming Christianity as true, one only needs to show that it possesses sufficiently good evidence to warrant belief.