Question #3 is:
How many persons are there in God? There are three persons in one God: the Father, the Son, and the Holy Spirit.
The memory verse is 2 Corinthians 13:14
May the grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit be with you all.
All analogies of the trinity break down (and in this funny little youtube video show how some of them are down right heretical) so it is hard to talk about the trinity with your child. Rather than trying to help your child “understand” the trinity, try helping your child “confess” the trinity. A God that we can understand completely would be a god of our own making anyway, so it should stand to reason that we can’t figure it out. But we can confess something to be true even though we can’t completely understand it.
By way of another bad analogy, I can’t understand how oxygen is absorbed into my molecules to make me live. It’s too complicated for me. But I believe that I must breathe. And that belief works out in me every time I take a breath. You don’t have to fully understand something to confess that it is true.
We believe that God is 3 in persons and one in essence, each person of the Trinity fully God, and there is one God. I can’t understand it, but I can believe it and confess it to be true.
Here’s another nice video from Alistair Begg that might help you think about how to talk to your kids about the trinity.