en_tn/mrk/14/38.md

that you do not enter into temptation

Jesus speaks of being tempted as if it were entering into a physical place. Alternate translation: "that you are not tempted" (See: rc://en/ta/man/jit/figs-metaphor)

The spirit indeed is willing, but the flesh is weak

Jesus warns Simon Peter that he is not strong enough to do what he wants to do in his own strength. Alternate translation: "You are willing in your spirit, but you are too weak to do what you want to do" or "You want to do what I say, but you are weak"

The spirit ... the flesh

These refer to two different aspects of Peter. "The spirit" is his inmost desires. "The flesh" is his human ability and strength. (See: rc://en/ta/man/jit/figs-metonymy)