Luke 9:48

‘For he who is least among you all, the same is great.'

Then He laid down one of His great maxims. ‘For he who is least among you all, the same is great.' In other words, God sees as great the one who is ready to do the lowliest tasks, and the one who willingly takes the lowest place, quite unconscious of the fact that he is doing so. Then God can move Him up higher (Luke 14:10). Note that he is great, not ‘the greatest'. None, even among men, are the greatest. There are no such comparisons among men whose hearts are true. Once there are such people cease to be great at all.

For men who argue about or assess their own greatness, or are too important to do the lowest task, are in His eyes the lowest of all. They are victims of the pride of life, and are not of the Father but are of the world (1 John 2:15). They have lost touch with the heart of the Father. For those who are truly great do not know that they are great, nor do they care. They simply do the Father's will.

Some see ‘he who is least among you' as the child previously mentioned. In that case His point is that greatness consists in having the innocent faith and willingness of a little child. Young children will usually do anything that they are asked because they desire to please. It is only as they grow older that they become awkward. In the same way the disciple should be willing to do anything that God sets before him in the circumstances of life, without any sense of it being too menial. But the moment that we do a menial task in order to be appreciated for it we cease to be great, for greatness consists in doing all things for God and for God alone without any thought of ourselves.

We Must Learn To Assess People In God's Eyes Not By Our Own Prejudices (Luke 9:49).

A further example of how the Apostles were becoming too important for their own good comes out in this example. They were becoming too aware of their own status, and overlooking the fact that they must allow God to decide the status of everyone. When therefore they saw a man casting out evil spirits in the name of Jesus they forbade him, because he was not ‘one of us'. They did not stop to consider that, unlike themselves with the demon-possessed boy, this man was being successful, which indicated that God was with him (contrast Acts 19:13). Later the early church would have to regulate such people because of the danger of heretics. But at this time that was no danger.