en_tn/1pe/03/02.md

having been eyewitnesses of your respectful, pure behavior

The abstract noun "behavior" can be translated with a verb. Alternate translation: "having seen for themselves that you behave sincerely and respectfully" (See: rc://en/ta/man/jit/figs-abstractnouns)

your respectful, pure behavior

Possible meanings are 1) "your sincere behavior toward them and the way that you honor them" or 2) "your pure behavior toward them and the way that you honor God."