Have children dramatize the story of Joseph being sold into Egypt by his brothers and then forgiving them (see "Dramatizations," TNGC, 165-66; Primary6, Lessons 15 and 17). 
As the children act out the story, stop them to ask questions such as

• "How do you suppose Joseph felt?" 
• "Why were the brothers afraid?"
• "How do you feel when someone forgives you?" 

Display words from Matthew 6:14 in random order. 
Have the children put the words in the correct order and then look up the scripture to check their answer.  Point out the word "if" and explain that the promise of forgiveness is conditional.  You may need to explain conditional with a few "if-then" statements, such as, "If you keep the commandments, then you will be blessed." 

Sing "Help Me, Dear Father" (CS, 99) and bear your testimony of forgiveness