I just taught my 9-yo an analogy about salvation. I had her smear a plate with butter. Then, I asked her if she should put it into the cupboard that way. (She said, "No.") I told her heaven is the cupboard, and the butter is sin, and the plate is her. I told her she cannot get into heaven because of her sin. Then, I asked her to rinse off the plate. Of course, it did not come clean. I said, "No matter how hard you try, you can't get the plate clean with just water. You need soap. Soap is part water and part grease, so it connects the two. It can lift off the grease." Then I asked her to apply the soap and rub and rinse it. Of course, it came clean. I said, "Jesus is the soap. He is both man (water) and God (oil), so he can connect man with God and can remove our sin so we can be with God in heaven when we die.

It has flaws, but this analogy did help her understand... I did have to clarify that Jesus is sinless and paid the price for our sin. That is how he takes care of our sin so we can be with God in heaven.