March 321
Constantine the Great, the first Roman emperor to become a Christian, officially proclaims Sunday to be the Christian day of worship, saying, “Let all judges and all city people and all tradesmen rest upon the venerable day of the sun.”
March 1536
John Calvin, a French theologian of the Protestant Reformation, publishes his groundbreaking Institutes of the Christian Religion, in Basel, Switzerland, in which he expounds the Calvinist doctrine of predestination, justification by faith alone and the supremacy of God in selecting individuals for salvation.
March 10, 1748
John Newton, captain of a slave ship, is converted to Christianity during a huge storm at sea. He eventually becomes an Anglican clergyman and writes the popular hymn “Amazing Grace.” Over the years, he collaborates with the poet William Cowper on a hymnal.