Harry Ironside was pastor of Moody Church in Chicago. An elderly man once came to him and said, “I will not go on unless I know I’m saved, or else know it’s hopeless to seek to be sure of it. I want a definite witness, something I can’t be mistaken about!”
Ironside replied, “Suppose you had a vision of an angel who told you your sins were forgiven. Would that be enough to rest on?”
The man replied, “Yes, I think it would. An angel should be right.” Ironside continued, “But suppose on your deathbed Satan came and said, ‘I was that angel, transformed to deceive you.’ What would you say?” The man was speechless. Ironside then told him that God has given us something more dependable than the voice of an angel. He has given us own Word that if we trust in Christ all our sins are gone. Ironside read 1 John 5:13 to the man: “I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life.” Then Ironside asked the man, “Is that not enough to rest on? It is a letter from heaven expressly to you.” The Holy Spirit used God’s promise to bring assurance of salvation to the man’s heart.