The Logos of God, who is fully divine by nature, became fully human, being composed just like us of an intellectual soul and a passible body, save only without sin. … in His love for humanity, He willingly appropriated the pain which is the end of human nature… He did this in order that, by suffering unjustly, He might uproot the principle of our being conceived through unrighteous pleasure, which tyrannizes our human nature. Moreover, He did it so that, with the Lord’s own death being not a penalty exacted for that principle of pleasure, like other human beings, but rather a death specifically directed against that principle, He might erase the just finality which human nature encounters in death, since His own end did not have, as the cause of its existence, the illicit pleasure on account of which He came and which He subjected to His righteous punishment. For in truth it was necessary that the Lord - who is by nature wise and just and capable - not, in His wisdom, ignore the means of curing us, nor, in His justice, arbitrarily save humanity when it had fallen under sin by its own free will, nor, in His omnipotence, falter in bringing the healing of humanity to completion. … He exhibited the equity of His justice in the magnitude of His condescension, when He willingly submitted to the condemnation imposed on our passibility and turned that very passibility into an instrument for eradicating sin and the death which is its consequence (Ad Thalassium 61.89).

St Maximus the Confessor