When is correction a helpful gift? When someone is compromising. It's in the Bible, Galatians 2:11, TLB. "When Peter came to Antioch I had to oppose him publicly, speaking strongly against what he was doing for it was very wrong."
Correction is helpful when it is motivated by love rather than condemnation. It's in the Bible, I Corinthians 4:14, TLB. "I am not writing about these things to make you ashamed, but to warn and counsel you as beloved children."
Correction is helpful for those who want to grow spiritually. It's in the Bible, Hebrews 12:7, TLB. "Let God train you, for he is doing what any loving father does for his children. Whoever heard of a son who was never corrected?"
Scripture is also the source of correction for people's lives. It's in the Bible, II Timothy 3:16,17, NIV. "All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work."