It’s amazing how a few letters here and there can make a word completely change meaning. The difference between “childish” and “childlike” is daylight and dark.
Jesus told the disciples to become childlike. That is, have the forgiving heart of a child. Don’t be too quick to judge harshly. Think the best in people–not the worst. Always scold in ways that you would want to be corrected. In essence–humble yourself and become “like” this little child.
Childishness has absolutely nothing to do with maturity. It is selfish. It’s wanting “my” way no matter what it costs you. Babies cry when they are wet, hungry, or hurting. They have no concept of things going on around them. The simply want it and they want it now.
God help us to have the heart of a child in the maturity of Jesus.