CHRISTIAN DOCTRINE SAYS THAT IT IS GOOD TO ENCOURAGE YOUR CHILDREN TO PRAY AND TO PRAY OFTEN

The Truth:  Johnny being a child will be asking God to do miracles. He will think of prayer more as a way to get what you want than as a form of submission to God. Encouraging children and teens to pray is encouraging them to want to manipulate reality by making things happen. It makes them too selfish. This can lead them to religiosity. Or it can lead to them ditching religion to be selfish. In either case, they will be made too selfish because of the irresponsible people who urged them to pray when they were in their childhood. Religion does more indirect evil than direct evil.
 
Miracles help make converts to the faith. Mostly what happens is that it is not the miracle that converts but people reading the story and thinking it rings true. So the stories not the miracles as such do the converting. That aside, faith is no good unless it is an act of union with God. In other words, people use their belief to unite with God. Miracles indicate the truth of divine teaching and the need for unity with God. So strictly speaking miracles are for bringing others to prayer.
Many miracles such as apparitions call for prayer.

All these things make prayer a distortion of spirituality and a self-directed lie.