Matthew 18:4

The Lord teaches that we cannot enter the kingdom of heaven unless we revert to the nature of children, that is, we must recall into the simplicity of children the vices of the body and mind. He has called children all who believe through the faith of listening. For children follow their father, love their mother, do not know how to wish ill on their neighbor, show no concern for wealth, are not proud, do not hate, do not lie, believe what has been said and hold what they hear as truth. And when we assume this habit and will in all the emotions, we are shown the passageway to the heavens. We must therefore return to the simplicity of children, because with it we shall embrace the beauty of the Lord's humility.

He calls infants all who believe through the hearing of faith; for such follow their father, love their mother, know not to will that which is evil, do not bear hate, or speak lies, trust what is told them, and believe what they hear to be true. But the letter is thus interpreted.

"Whoever humbles himself like this child, he is the greatest in the kingdom of heaven." Just as this child whose example I show you does not persist in anger, does not long remember injury suffered, is not enamored inordinately by the sight of a beautiful woman, does not think one thing and say another, so you too, unless you have similar innocence and purity of mind, will not be able to enter the kingdom of heaven. Or it might be taken in another way: "Whosoever therefore humiliates himself like this child is greater in the kingdom of heaven," so as to imply that anyone who imitates me and humiliates himself following my example, so that he abases himself as much as I abased myself in accepting the form of a servant, will enter the kingdom of heaven.

(Verse 4.) Therefore, whoever humbles himself like this little child, he is the greatest in the kingdom of heaven. Just like this little child, whose example I give to you, does not persist in anger, does not hold grudges, does not delight in seeing a beautiful woman, does not think one thing and say another; in the same way, unless you have such innocence and purity of heart, you will not be able to enter the kingdom of heaven. Or in another way: Therefore, whoever humbles himself like this little child, he is the greatest in the kingdom of heaven. Whoever imitates me and humbles himself as I have humbled myself, taking the form of a servant, he will enter the kingdom of heaven.

Or otherwise; Whoso shall humble himself as this little child, that is, whoso shall humble himself after My example, he shall enter into the kingdom of heaven. It follows, And whoso receiveth one such little one in my name, receiveth me.

Hyperichius said, 'The tree of life is high, and humility climbs it.'

And Jesus called a little child unto Him, and set him in the midst of them, and said, Verily I say unto you, Except ye be turned back, and become as little children, ye shall not enter into the kingdom of heaven. Whosoever therefore shall humble himself as this little child, the same is greatest in the kingdom of heaven. When the Lord sees the disciples under the sway of the passion of vainglory, He restrains them, showing them the way of humility by means of an unassuming child. For we must be as children in the humility of our mind, but not be infantile in our thoughts; and we must be as children in guilelessness, but not in foolishness. By saying, "Except ye be turned back," He showed that they had gone from humility to vainglory. You must turn back again to that place, which is humility, from which you departed.

(interlin.) Except ye be converted from this ambition and jealousy in which you are at present, and become all of you as innocent and humble in disposition as you are weak, in your years, ye shall not enter into the kingdom of heaven; and since there is none other road to enter in, whoso shall humble himself as this little child, the same is greatest in the kingdom of heaven; for by how much a man is humble now, by so much shall he be exalted in the kingdom of heaven.

And whoever shall receive one such little child, i.e., whoever is an imitator of childlike innocence, he is the greater, because the more humble, the more exalted: because he who humbles himself, shall be exalted, Luke 18:14. But a question can arise: for it seems that this is not true, because perfection consists in charity; therefore where there is greater charity, there is greater perfection. It must be said that humility necessarily accompanies charity. And you can see this if you consider who is humble. For just as in pride there are two things, a disordered affection and a disordered estimation of oneself, so, conversely, it is in humility, because one does not seek one's own preeminence, and likewise does not consider oneself worthy. This necessarily follows upon charity. Every man desires the preeminence of what he loves. Therefore the more a man has of humility, the more he loves God, and the more he despises his own preeminence, and the less he attributes to himself: thus the more a man has of charity, the more he also has of humility.