The Greek word charis — grace — carries a specific freight that English flattens. In Greek culture, charis referred to a gift given freely by someone of higher standing, with no obligation of repayment implied. It was favor extended from abundance, not from calculation. Ephesians 2:8–9 defines salvation itself in these terms: "For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: not of works, lest any man should boast." Three consecutive negatives: not of yourselves, not a gift you generated, not of works. The positive is single: gift of God.
Romans 5:20 contains one of the most unexpected formulas in Paul's theology: "where sin abounded, grace did much more abound." The word for "much more abound" is hypereperisseusen — to overflow beyond all measure, to exceed in every direction. Grace is not calibrated to meet sin at the same level. It overshoots. The more honest you are about how much you have needed grace, the more you understand what that word is trying to hold.
Titus 2:11 adds the active dimension that grace is always producing: "For the grace of God that bringeth salvation hath appeared to all men, teaching us." The word "teaching" is paideuousa — to educate, to train as a parent trains a child. Grace is not passive. It arrived with an agenda: to teach you to live differently. The same grace that forgives is the grace that forms.
Commentary is from a charismatic Protestant perspective, drawing on KJV text and public-domain sources including Spurgeon, Andrew Murray, and Matthew Henry.