Many non-Christians know the hymn "Amazing Grace" but may not know what grace means. One day when evangelist D. L. Moody was studying the meaning of God's grace, he dashed into the street and shouted to the first man he saw, "Do you know grace?" Mystified, the man replied, "Grace who?" No doubt Moody then explained grace —that God has compassion on sin-sick people and freely offers them forgiveness and new life through faith in Christ.
I heard of a man who had lived a troubled life and died without understanding the message of God's grace. A minister had talked to him and encouraged him to come to church, but his response was, "I'm too undeserving." He didn't know that God's grace is for the undeserving.