My sibling and I have competed since childhood and I still measure myself against them. How do I let that go?

“And Eliab his eldest brother heard when he spake unto the men; and Eliab's anger was kindled against David, and he said, Why camest thou down hither? and with whom hast thou left those few sheep in the wilderness? I know thy pride, and the naughtiness of thine heart; for thou art come down that thou mightest see the battle.”

The moment David starts asking questions about Goliath, his oldest brother Eliab turns on him and accuses him of pride and of abandoning a few sheep. The accusation says far more about Eliab, who is standing in the same paralyzed army, than it does about David. Scripture records the sibling contempt honestly and then simply moves past it. The rivalry is real, and it is not the story.

“But let every man prove his own work, and then shall he have rejoicing in himself alone, and not in another.”

Paul tells the Galatians to examine their own work, and says any satisfaction should come from the work itself rather than from a comparison with someone else. He is describing the mechanics precisely. Joy that depends on outperforming another person is borrowed rather than owned, and it can be taken back from you at any moment by their good news.