en_tn_condensed/col/03/12.md

as God's chosen ones, holy and beloved

This can be made active. Alternate translation: "as those whom God has chosen for himself, whom he desires to see live for him alone, and whom he loves" (See: rc://en/ta/man/jit/figs-activepassive)

put on a heart of mercy, kindness, humility, gentleness, and patience

The "heart" is a metaphor for feelings and attitudes. Here it is spoken of as if it had certain feelings and attitudes, and as if it were clothing to wear. Alternate translation: "have a merciful, kind, humble, gentle, and patient heart" or "be merciful, kind, humble, gentle, and patient" (See: rc://en/ta/man/jit/figs-metaphor)