Baptism

I have 3 children. They decided to be baptized.
The pastor asked a written testimony to each one.
They thought it should be some kind of paranormal experience... The younger wrote that he believed in the Lord because he helped him to pass in a school test but he was very disappointed with such a small contact with God.
I told him that such experience was a very weak reason to believe, but I affirmed him that it is not necessary to see a fire falling from heaven or some kind of extra terrestrial experience.
I told him that he should affirm his belief in Jesus who was crucified on the cross for him due to the Word.
I really hope the Lord guides each one of them.
In some way, it is certainly an extra terrestrial experience... but till now, the Lord did not show me any special effects and I am in peace with that. Thinking better, I had some kind of strange things. I had a lot of nightmares that were gone by prayer. I see Jesus changing natural desires. Isn't it supernatural?