Alternatively, you could use coloring pages as a reward that you give to your child when he or she does something good, like says thank you, gives a compliment, or helps out before being asked. Not only does it reward them by giving them an activity they will enjoy doing, but it also demonstrates to them that it is good to do things that please the Lord.
Give it a try! Print out a few Christian coloring pages for your kids and see how they respond. It is a great way to keep them thinking about the things of the Lord.