Two young men with opposite lives from opposite sides of the world unwittingly exchange destinies as one encounters the other, and the other encounters a vision of God.

My problem with this logline is that I don't understand what do you mean with "exchange destinies". For me you need to explain that a little better.

Like it is this logline doesn't make me interested to know the full story.

Hello,
you can do better if you don't "explain" the story: try to tell the story instead.

I would sum up this logline in one word - Vague.

The purpose of the logline it so we (or a potential producer, actor, director, etc) can imagine the movie, and hopefully it intrigues them enough to want to find out more. But from this logline we could imagine a thousand different versions of the movie and be none the wiser what yours was supposed to be.

Try including some specifics.