# their ... they

The pronouns "their" and "they" refer to the Jewish people who did not believe.

# but you stand firm because of your faith

Paul speaks of the Gentile believers remaining faithful as if they were standing firm and no one could move them. Alternate translation: "but you remain because of your faith" (See: [[rc://en/ta/man/jit/figs-metaphor]])

# be arrogant in your thoughts

"think that you are better than you are" or "be proud"