How can you? You reject Christianity, which is true.
I reject everything based on faith, Christianity, the occult, Astrology, Judaism, the Flying Spaghetti Monster, etc.
The basis of the Christian faith is the revealed word of God, in other words Prophecy. Can you produce a single precise, accurate and verifiable prophecy that has been fulfilled?
You claim to believe science, but science isn't about truth at all, so you have no basis for learning about truth from there.
What my senses show me is truth. Forgive me if when you want me to worship the Flying Spaghetti Monster, and can't show it to me, that I doubt your truth : )
So just what is your source of "truth"?
When I hold my wife in my arms, that is all the truth I need : ) I can feel her, smell her, hear her, in other words it is truth.
Read the Gospels. It tells you there. And that's just to start with.
What my senses show me is truth.
That's just your experience. The perception of your senses is not necessarily an accurate recording of what is really true.
True is what's true regardless of who is perceiving it. Otherwise, there would be billions of different versions of truth based on billions of different people's perceptions of reality, and that can't be.
If it was, however, as you believe, that everyone has their own version of truth, then it's just as valid as anyone else's and then no one has any right or justification, for telling someone else that they are wrong, because everybody's truth is right.