Growing up and remaining "like a child"

I struggle.

Often.

Daily.

Hourly.

Moment by moment.

I'm seeking the delicate balance between maturing and staying childlike.

I'm not one of those 30-somethings that's trying to relive my high school and college years, acting childish in a more mature body. That's not what I'm talking about at all.

I'm talking about my faith and spirit. I want to "grow up" and mature, but also maintain the belief, hope, and wonder of a child that hasn't known disappointment and disillusionment.