There is an interesting set of verses in Matthew that talks about how we should be like children – Matt 18:1-5
At that time the disciples came to Jesus, saying, “Who is the greatest in the kingdom of heaven?” And calling to him a child, he put him in the midst of them and said, “Truly, I say to you, unless you turn and become like children, you will never enter the kingdom of heaven. Whoever humbles himself like this child is the greatest in the kingdom of heaven. Whoever receives one such child in my name receives me”
It’s an interesting concept to think that we should be like a child, my experience of children can be that they moan and cry about all the things they want, however I doubt this is what Christ is alluding to.
I think what Jesus means is that we should approach God with complete trust and belief. When a parent tells a child something, that child will believe that parent without a doubt, they don’t doubt or ignore you, rather they follow your lead and trust in you.
This is what we should be like to God, when we learn of what he wants of us and what he has promised for us. We should believe in him like a child believes in their parents, with full trust that everything will turn out how we have been told.