What does it mean to be child-like?
To me it means to simplify. Children live off of a simplistic base knowledge. Things are not jaded in their eyes.
The problem of becoming an adult is that we over complicate the majority of things we are involved in.
Go back to your child-like sense of adventure and curiosity. Dig deeper into the love of the Heavenly Father. Simplify and remove those things that over complicate.