In the beginning when God created man he set him in paradise (the divine holy scripture says [Gen. 2:20]) adorned with every virtue, and gave him a command not to eat of the tree in the middle of paradise.
He was provided for in paradise, in prayer and contemplation in the midst of honor and glory; healthy in his emotions and sense perceptions, and perfect in his nature, as he was created.
For, in the likeness of God did God make man, that is, immortal, having the power to act freely, and adorned with all the virtues.
When he disobeyed the command and ate of the tree that God commanded him not to eat, he was thrown out of paradise (Gen. 3) and fell from a state in accord with his nature to a state contrary to nature, i.e. a prey to sin, to ambition, to love of the pleasures of this life and the other passions; and he was mastered by them, and became a slave to them through his transgression.
Then, little by little evil increased and death reigned. There was no more piety, and everywhere was ignorance of God.
[…] The good God then gave the law as a help—for their conversion, for putting right what was evil, but they did not reform. He sent the prophets, but they were unable to do anything.
For evil prevailed as said Isaiah, no injury, no bruise, no wound was cauterized; no chance of soothing dressings; no oil, no bandaging of wounds (Isaiah 1:6), as much as to say that the evil was not in one member, or in one place, but in the whole body. It encompassed the whole soul and all its powers.
Everything was a slave to sin; everything was under the control of sin. As Jeremiah said, We would heal Babylon, but she would not be healed (Jer. 51:9).
All the same she is not healed; she has not been converted, she has not feared, she has not turned from her wickedness. In another place he says, they have not submitted to discipline (Jer. 2:30), that is, to correction and instruction. And in the psalm it says, All food did their soul abhor, and they drew nigh even unto the gates of death (Ps. 106:18).
Then finally the most good and man-loving God sent His Only Begotten Son; for God alone could heal such a disease.
Dorotheos of Gaza (505-565 or 620): Conference on Renunciation @ Pravoslavie.