"I tell you the truth, unless you change and become like little children you will never enter the kingdom of heaven." (Mt 18:3 NIV)
"...become like little children" doesn't necessarily mean admitting weakness. Jesus spoke these words to the disciples after they asked Him "Who is the greatest in the kingdom of heaven?" (see Mt 18:1). They were trying to maneuver to line up positions of honor for themselves in His kingdom.
The challenge for the disciples to become like little children was a challenge not to become weak, but to stop their deceitful thinking and acting. Little children are truly innocent; there is no guile, no deceitfulness in them. They have no tricks up their sleeves. They have no personal agendas that control their thinking and acting. To become like a little child is to stop focusing on myself and my desires; to stop pushing my personal agenda.
SLE