There is one eternal principle which will be valid as long as the world lasts. The principle is—Forgiveness is a costly thing. Human forgiveness is costly. A son or a daughter may go wrong; a father or a mother may forgive; but that forgiveness has brought tears ... There was a price of a broken heart to pay. Divine forgiveness is costly. God is love, but God is holiness. God, least of all, can break the great moral laws on which the universe is built. Sin must have its punishment or the very structure of life disintegrates. And God alone can pay the terrible price that is necessary before men can be forgiven. Forgiveness is never a case of saying: “It’s all right; it doesn’t matter.” Forgiveness is the most costly thing in the world.

William Barclay in The Letter to Hebrews, Christianity Today, October 5, 1992, p. 48