Paul finishes his instructions on what believers should not do and ends with what they must do.
“Put away” here is a metaphor for not continuing to have certain attitudes or behaviors. AT: “You must not allow these things to be part of your life: bitterness, rage, anger” (See: rc://en/ta/man/translate/figs-metaphor)
“Instead, be kind”
“gentle” or “full of compassion” (See: rc://en/ta/man/translate/figs-idiom).