I have always been terribly interested in comparative religion. Ideas have consequences, and few ideas in human history have had greater consequences than those that fit under the general heading of religion. That is true at both the personal level -- there's a wonderful line in a novel in which a woman reflects on how very different her life would be if she only worshiped different gods -- and at the human history level. Had monotheism never arisen, for example, the world would be a very different place today. And it is for that reason that I'm actually less interested in the theological trivia of any given religion, even though I'm reasonably well versed on the theological trivia of most of them, than I am in how any given individual's life is actually different than it would be if he worshiped other gods.
When I was living in New Orleans, I took advantage of my stay there to learn about voodoo, which, after all, is another comparative religion. The woman I studied under said something that struck me then as wrong, but which over time I've come to believe she may have had a point about. She told me that everyone, of all faiths, believes basically the same thing (minus theological trivia that varies from one faith to another) and they just have different names for it. The example she gave is that voodoo teaches about the existence of spirits; the dear departed to whom the living look for inspiration, guidance and aid. Christians, on the other hand, believe in saints, which are the dear departed to whom the living look for inspiration, guidance and aid, albeit Protestants less so than Catholics. Voodoo has its spirits; Christianity has its saints; but both of them basically boil down to the same fundamental concept: Those who have gone before continue to take an interest in human affairs and can be called on for help. The idea that everyone believes essentially the same thing is, incidentally, also the central tenet of the Bahai faith: All religions are valid.
In college I studied the major schools of Greek philosophy. Later, when I was learning about the great Eastern philosophies, I was immediately struck by how very similar they were to what the Greeks came up with. Confucianism is basically a Chinese version of Greek stoicism, and Greek epicurianism is effectively a Western incarnation of Taoism. Yes, there are bits of theological minutiae that distinguish them, but overall it's the same general idea.
So what is the cash value of all of this? I said at the beginning of this post that I was less interested in theological trivia than I am in whether anyone's religion has actually made them a better person. And so, for an example of what I mean, let us take up the theological question of whose wife will she be in the judgment.
The Sadducees, who didn't even believe in the resurrection, once came to Jesus with a question: There was a woman who had been married seven times, and none of the marriages had produced any children. She then died herself. Whose wife will she be in the resurrection? OK, why would the Sadducees, who didn't even believe in the resurrection, ask such a question?
As it happened, Jesus had recently ministered to a Samaritan woman at the well, who had had five husbands, and was then living with a man to whom she wasn't married. The Sadducees had two choices. They could either be happy that this woman who had spent an entire life in isolation, pain, alienation and loneliness, had met Jesus and something wonderful had happened as a result. Or, they could start a doctrinal dispute over whose wife she would be in the judgment (even though they couldn't even get their facts straight and tacked on a couple of extra husbands just for good measure). Because they couldn't bear the thought of being happy for her, they invented a theological dispute.
Now, theology has its uses, and Jesus did in fact answer their question (after first telling them it was based on a flawed premise). But at the end of the day, the life-changing event was far more important than the theological trivia in which the religious leaders wished to engage.
So, you want to convince me that your particular religion is the true one? Don't even bother trying to dazzle me with your theology. Show me that it's changed your life. Because if it hasn't, I'll go amuse myself by finding some Nietzsche to read.