Childish vs Childlike

The meaning of "Unless you change and become like little children, you will never enter the kingdom of heaven." is to surrender. 

Little children are used as an example because they haven't (yet) been tainted by the insanity that plagues the world. They enter the world with no expectations, no demands, no judgments, no fears, no cares, no worries, no ill will, no resentment, etc. All they have ate natural abilities to communicate their basic needs.

Little children know they don't have the answers to what they need and have no problem asking for help. They are dependent on their care taker and completely trust him/her/them for their needs. 

Little children are to be used as an example of how to live because there is really nothing to it! "Oh to be a kid again" is often said/heard because time is irrelevant to little children. They do not concern themselves with things they don't control (Time.) They don't worry about how things are going to happen and they're not concerned with whether it will happen or not.  

Doubt, Fear, Anxiety, Worry, Stress, etc. comes as a result of forgetting who is in control (and it's not you!) which is where Pain and Suffering come in to play. It is here childish behavior is learned and the Self is recognized as all that matters. It's at this point that greed, envy, jealously, revenge, etc. take form because trust is no longer in the care giver but now in "Me," "Myself," and "I." Selfish behavior is a result of childish thoughts like "what about me?" "that's mine!" "I had that first!" etc. 

Remind yourself Who is ALWAYS in control and you will return to your childlike state and know all is well despite how your current life circumstances may seem and you will have entered the kingdom of Heaven, it's called Peace. Peace