whoever humbles himself like this child is the greatest in the kingdom of heaven (Matthew 18.4)
Humbling ourselves can only be understood when we realise what it is not. Neither a lack of self confidence nor a readiness to endure humiliation is what we have here. Jesus is not speaking of something forced upon a person, by circumstances or by others. He is talking about something a person chooses: whoever humbles himself.
Jesus speaks this way because humbling himself is something that He Himself undertakes. Paul speaks, in Philippians 2.8, of how Jesus humbled himself and became obedient to death - even death on a cross! Humility is something that takes place deep within a person. It is an inner attitude of self abasement, placing ourselves below others: so we can look up at them. Where people can in humility consider others better than yourselves (Philippians 2.3).
And because this is an inner attitude, it is something we cannot easily detect by a person’s demeanour. It is evidenced rather by its fruit in relationships. Where genuine interest in others is expressed and pursued. An inclination to see potential, not simply faults; strengths, not simply weaknesses. This is why we, like the disciples, find it so hard to humble ourselves. It is so much easier to compete and compare, criticise and complain.
To be great in God’s eyes, Jesus invites us to adopt the perspective of the least. It’s not easy. It’s not very self-affirming. It’s a bit like taking up a cross.