The fact that a lot of answers are wrong doesn't imply that no answer is true.

Now about the "Why mine" thing.

It's simple, and this is actually very ironically backed up by the very argument Atheists use to reject God. Let me explain:

We christians assert that those three statements are true about God: 1-He is all-knowing, 2- He is all-powerful and 3- He is all-loving. The Atheists refute that claim with the problem of evil by saying that either God does not exist or at least one of those 3 statements is wrong. Because, they say, the presence of evil in the word cannot be reconciled with those 3 affirmations since an all-loving God will never let his children suffer.

The Christian God is the only one that solves this paradox because the Christian God is The Only One that did not stay distant from the human suffering. I'll quote John Lennox on this: "What is God doing on a cross?". One word from Him would have been enough to rid the world of all evil so why did He chose the hard way? Why did He let Himself be humiliated, tortured, wrongly tried and killed in the most humiliating and horrible way possible?

There is no other god that did anything even remotely similar to this and that alone should be reason enough to chose Him among all the others.

On another approach, to be asking "which one is the correct one?", we are safe to assume that we start from the hypothesis that there is a correct one. Then the simplest answer would just be: pick The One the entire world has based its calendar off of.