Becoming Childlike

I heard a sermon tonight while working about becoming childlike. Unless we become like little children, we wont enter the Kingdom of Heaven. I don't feel I have fully become childlike yet. I am trying to but years of pride and stubborn self-will has really taken a toll on my own soul. Getting back to that original, innocent child-hood state is difficult for me right now but I am trying to get back to it. I know that nothing else matters. I know that childlike state is where so much freedom, joy, and peace is. Getting back to that state is basically the hardest thing I've ever done but there is no other way to be.