John Newton kept the twenty-first of March as a holy day for the rest of his life. On that date in 1748, a storm off the coast of Ireland nearly sank his ship, and he prayed for mercy and meant it. He came ashore and started reading the Bible. Two years later he took command of the Duke of Argyle and sailed for the coast of Africa to buy human beings.

He made two more voyages as captain of the African. A stroke ended his sailing in 1754, and he kept money in slaving ventures after that. In 1788, he published Thoughts Upon the African Slave Trade and called it a confession that came too late. He wrote of "a business at which my heart now shudders."

The man who wrote that sentence and the man who paced the decks of those ships prayed to the same God. Over forty years, whatever had blocked his view came off one piece at a time.