Talk: Ask the children to list off things that they should not do. Write them down on a piece of paper. Then put them into the open envelope and seal it. Talk for a while about forgiveness. Then go back to your double envelope. Open the first envelope and take out the blank piece of paper. The children should think that this is the paper on which they wrote the list of things they should not do. Ask for a volunteer to read the list. Of course they can’t because the page is blank. I tend to say ‘one other thing you shouldn’t do is cheat’, and explain how I switched the pieces of paper. You can then explain how God takes the wrong things we have done and removes them. He really can make the list turn blank.
Useful texts: Psalm 103:12; Isaiah 1:18.