Mailvox: how do you know?
1. Christian principles predict human behavior and its concomitant consequences better than anything else I've witnessed or studied. ... Within its intellectual tradition, Christianity provides an explanation for everything from unhappy housewives to the inevitability of war to the marginal utility of wealth. Regardless of whether one accepts those explanations, a reasonable one almost always exists. While not always intellectually credible at first glance, on the whole it is more intellectually coherent than any other philosophy or religion.
2. I have witnessed and experienced the power of Jesus Christ in my life and in the lives of those around me. The main reason I became more open to the possibility that Christianity might indeed be something to consider was witnessing some dramatic changes in the White Buffalo, only to learn after the fact that he had become a Christian some time before. I was completely unaware that he'd even been attending church, much less become a Christian, because I never, ever, got up before noon and he was going to an early service. I can still remember overhearing a conversation of his, one totally unrelated to religion, and wondering if the Pod People had come in the night.
So, even if Christianity was, by its own lights, false, it would still be an uncannily powerful placebo and one that one would be churlish, if not downright evil, to deny others. The very hatred that so many betray for Christianity, as opposed to Islam, Judaism (the religion, not the people) and Buddhism is, to me, testimony of the veracity of the Christian worldview.
3. The existence and persistence of evil, great and small. I believed in the tangible reality of evil before I believed in the existence of God. The one requires the other, for without God, there is no evil, there is only opinion or a lack of perfect utility. Indeed, even if Christianity is nothing but a human construct, I'll take it on that Voltairean grounds alone, for it is a construct that has served humanity longer and better than any other.