[It] was not right that the restoration of human nature should be left undone, and that it could not have been brought about unless man repaid what he owed to God. This debt was so large that, although no one but man owed it, only God was capable of repaying it, assuming that there should be a man identical with God. Hence it was necessary that God should take man into the unity of his person, so that one who ought, by virtue of his nature, to make the repayment and was not capable of doing so, should be one who, by virtue of his person, was capable of it (emphasis mine).
Anselm of Canterbury (1033-1109), The Major Works, “Cur Deus Homo,” 348.
Since therefore the children share in flesh and blood, he himself likewise partook of the same things, that through death he might destroy the one who has the power of death, that is, the devil, and deliver all those who through fear of death were subject to lifelong slavery. For surely it is not angels that he helps, but he helps the offspring of Abraham. Therefore he had to be made like his brothers in every respect, so that he might become a merciful and faithful high priest in the service of God, to make propitiation for the sins of the people (emphasis mine). For because he himself has suffered when tempted, he is able to help those who are being tempted. – Hebrews 2:14-18