Matthew 18:5

But how can he who has been converted, and become as a little child, be yet liable to be scandalized? This may be thus explained. Every one who believes on the Son of God, and walks after evangelic acts, is converted and walks as a little child; but he who is not converted that he may become as a child, it is impossible that he should enter into the kingdom of heaven. But in every congregation of believers, there are some only newly converted that they may become as little children, but not yet made such; these are the little ones in Christ, and these are they that receive offence.

Wherefore He brought it in, and set it in the midst; and not at this merely did He conclude His discourse, but carries further this admonition, saying, "And whoso shall receive such a little child in my name, receiveth me." "For know," saith He, "that not only, if ye yourselves become like this, shall ye receive a great reward; but also if for my sake ye honor others who are such, even for your honor to them do I appoint unto you a kingdom as your recompence." Or rather, He sets down what is far greater, saying, "he receiveth me." So exceedingly dear to me is all that is lowly and artless. For by "a little child," here, He means the men that are thus simple and lowly, and abject and contemptible in the judgment of the common sort.

For whoever is such that he imitates Christ's humility and innocence, Christ is received by him; and by way of caution, that the Apostles should not think, when such are come to them, that it is to themselves that the honour is paid, He adds, that they are to be received not for their own desert, but in honour of their Master.