en_tn/jud/01/21.md

Keep yourselves in God's love

Remaining able to receive God's love is spoken of as if one were keeping oneself in a certain place. (See: rc://en/ta/man/jit/figs-metaphor)

wait for

"eagerly look forward to"

the mercy of our Lord Jesus Christ that brings you eternal life

Here "mercy" stands for Jesus Christ himself, who will show his mercy to the believers by making them live forever with him. (See: rc://en/ta/man/jit/figs-metonymy)