I still remember - 24 years later - what my pastor said when he retired (I was 12) - be very, very careful about false gods.
To our sixth graders, two messages:
1. It really does matter if God is in your life
There's a difference between knowing about God and actually believing in him (trusting him)
Ex: Like the difference between seeing sunlight through a window and breaking through the window to benefit from the light fully. Behind the glass, you get some benefit, but it isn't until you get surrounded by the light that you derive the full benefit. Likewise, it's OK to know there is a God, but best to actually have God. No one can teach you that - it must come by faith, because you are willing!
2. God wants to save every part of your life.
The Woman at the Well (John 4) - initially it was Jesus asking her for a drink; it ended up with her asking him for living water.
We all like receiving gifts, but most of us settle for gifts that will spoil or fade. God wants to give you gift after gift, but - we don't get the choice of keeping certain parts of our life "off limits" to him. If you let him in, you're letting him into all the parts.
"God doesn't want to be a part of your life...he wants to be a part of all of the parts."
Ex: When you clean underneath your bed, you'll usually find lots of things you'd forgotten were there. When we ask God to "search our hearts", we are giving him permission to bust down the doors to every part of our lives.