en_tn/gal/02/17.md

while we seek to be justified in Christ

The phrase "justified in Christ" means justified because we are united with Christ and justified by means of Christ.

we too were found to be sinners

The words "were found to be" are an idiom that emphasizes that "we are" certainly sinners. Alternate translation: "we see that we also certainly are sinners" (See: rc://en/ta/man/jit/figs-idiom)

Absolutely not!

"Of course, that is not true!" This expression gives the strongest possible negative answer to the preceding rhetorical question "Does Christ become a servant of sin?" You may have a similar expression in your language that you could use here. (See: rc://en/ta/man/jit/figs-rquestion)