A thing is said to be necessary for a certain end in two ways. First, when the end cannot be without it, as food is necessary for the preservation of human life. Second, when the end is attained better and more conveniently, as a horse is necessary for a journey. In the first way it was not necessary that God should become incarnate for the restoration of human nature. For God of His omnipotent power could have restored human nature in many other ways. But in the second way it was necessary that God should become incarnate for the restoration of human nature. Hence Augustine says, “We shall also show that other ways were not wanting to God, to Whose power all things are equally subject; but that there was not a more suitable way of healing our misery.” Now this may be considered in regard to our advancement in good.

First, with regard to faith, which is made more certain by believing God Himself Who speaks; hence Augustine says, “In order that man might journey more trustfully towards the Truth itself, the Son of God, having assumed human nature, established and founded faith.”

Secondly, with to hope, which is thereby greatly strengthened; hence Augustine says, “Nothing was so necessary for raising our hope as to show us how deeply God loved us…And what could afford us a stronger proof of this than that the Son of God should become a partner with us of human nature.”

Thirdly, with to charity, which is greatly enkindled by this; hence Augustine says, “What greater cause is there of the Lord’s coming than to show God’s love for us?’ And he afterwards adds, “If we have been slow to love, at least let us hasten to love in return.”

Fourthly, with to well-doing, in which Christ set us an example; hence Augustine says, “Man who might be seen was not to be followed; but God was to be followed, Who could not be seen. And hence God was made man, that He Who might be seen by man, and Whom man might follow, might be shown to man.”

Fifthly, with regard to – the full participation of the Divinity – which is the true bliss of man and the end of human life; and this is bestowed upon us by the humanity of Christ; for Augustine says: “God was made man, that man might be Godlike.” (3a, q. 1. a. 2.)