en_tn/1co/02/11.md

For who knows a person's thoughts except the spirit of the person in him?

Paul uses this question to emphasize that no one knows what a person is thinking except the person himself. Alternate translation: "No one knows what a person is thinking except that person's spirit" (See: rc://en/ta/man/jit/figs-rquestion)

spirit of the person

This refers to a person's inner being, his own spiritual nature.

no one knows the deep things of God except the Spirit of God

"only the Spirit of God knows the deep things of God"