Bhagavad Gita, Chapter 17, Verse 3

The Shraddhâ of each is according to his natural disposition, O descendant of Bharata. The man consists of his Shraddhâ; he verily is what his Shraddhâ is.

What someone has faith in defines who they are.

Krishna doesn't separate belief from identity, he collapses the distance between them. Faith, in this account, isn't just a feature of a person, it's the person.