What makes your faith true?

[Odoital77]

Because it corresponds to reality, is coherent, makes sense of itself, etc...  It's for the same reasons that other things are true.

Which parts?

The contradictory bits or those which have been proved scientifically not to have happened?

I'm not aware of contradictory bits or those which have been disproven scientifically.  For example, I don't hold to a literal 6 day creation view.  The Bible is filled with multiple kinds of literature written from various perspectives, both gentile and Jew, which have to be taken into account.  Most of the time, when I run into apparent contradictions or asserted scientific disproofs, I'm usually looking at misapprehensions on the part of the objector or worse, outright straw men that the objector knows to be false characterizations of the Christian point of view or my point of view.  So I really would have to ask for some kind of clarification as to what you mean, specifically?