Opening - Game with no instructions / no rules
Something I have done with groups of children when introducing a lesson on the 10 C's:
Tell the children you are going to play a game today.
Have the children count off, or in some way divide up into two or more teams.
Give each team a ball, bean bag, frisbee, or something like that.
Tell them that when you say GO the game begins.
Count to 3 and say GO.
The children will not know what to do, how to begin, or even what the game is. They will not hesitate in telling you that you have forgotten a very important part of playing a game- THE RULES!.
This will lead into your discussion about the rules God gave us, and why God gave us the rules.
You might even start over with the game, this time with an explanation of the rules. Let the children play and then ask them which way was more fun.