I’m a Catholic Christian. I don’t forsee that ever changing. But, it might be interesting to imagine what I would believe if somehow I was convinced of the falsity of Christianity.
First of all, what would it mean for me not to be a Christian? I believe in Christianity for several reasons. Among them is the fact that, to me the Story of Christianity is both plausible and beautiful. It appears, to me, to have the Truth. More on this later.
Now, belief in Christianity implies many moral, theological, and philosophical, beliefs, but what belief in Christianity most means for me philosophically is that it implies the existence of Reason. Christianity means that Reason is God, God is Reason. “In the beginning was the Word [=Logos], and the Word was with God, and the Word was God” (Jn 1:1). So if I no longer believed in Christianity, I would no longer believe that logic was a valid tool for trying to understand the nature of the [Gg]od(s).
If I no longer believed in Reason, what would I be left with? I say, Story. If Reason does not exist, only reason, I would think that all that matters is the substance of the Story. The plausibility of the Story would be irrelevant, and the plausibility of the truths implied by that story would be irrelevant. All that would matter would be the beauty of the Story and of its implications.
And the most interesting Story (apart from that of Christianity) is to me that of Paganism. By this I don’t mean neo-paganism; that disgusts me, for the same reason that Hitler disgusted Tolkien. The practitioners of neo-paganism are
Ruining, perverting, misapplying, and making for ever accursed, that noble, northern spirit, a supreme contribution to Europe, which I have ever loved, and tried to present in its true light. Nowhere, incidentally, was it nobler than in England, nor ever more early sanctified and Christianized.
But Paganism, the original Paganism, that existed before Christianity; that is truly interesting. (Even now, it seems somewhat innocent to me because it was not fighting against Christianity; it simply did not know of the existence of Christianity.) The stories are fascinating. And the talionic, honor-focused, warrior ethic they imply are very tempting. So, if I cared not for the veracity of what I believed, but only for how interesting it was to believe it, I would be a pagan.
For the same reason, I cannot imagine myself ever becoming Muslim. They believe in a God who is not rational, and who cannot be reasoned about. This reminds me of an exchange in Perelandra between Weston [who is possessed by the Devil] and Ransom. Weston [the devil] says, “But don’t you believe in him because he is spirit?”. “Of course not!” Ransom replies. “We believe in him because he is good!”. It seems to me that Islam makes the same mistake Weston tries to convince Ransom of. They bow to a tyrant because he is powerful, instead of to a king because he is all-good. I could never do that.
So, in conclusion – I am a Christian. That will never change, unless something rather strange happens. But if that did, what would I believe? Well, I could maybe become a Paynim. But I could never become a Mussulman.