'In the Faith' in the Bible

[And] this testimony is true. [So], for this reason you should rebuke them severely, so that they will be sound in the faith,

Older men should be sober-minded [See note at I Tim. 3:2], dignified [i.e., respectable], sensible, sound in the faith [or, "in their faith"], in their love and in their perseverance.

All those who are with me send you their greetings. Greet those who love us in the faith [i.e., our fellow Christians]. May God's unearned favor be with all of you.