Fall of man

And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons. And they heard the voice of the LORD God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the LORD God amongst the trees of the garden. Genesis 3:7-8

For the scriptures state clearly how God from the beginning planted a tree [of knowledge and a tree] of life in the midst of Paradise, revealing life through knowledge; and because our first parents used it not genuinely they were made naked by the deceit of the serpent. Letter to Diognetus (A.D. 125-200) ch.12

For as it was not possible that the man who had once for all been conquered, and who had been destroyed through disobedience, could reform himself, and obtain the prize of victory; and as it was also impossible that he could attain to salvation who had fallen under the power of sin,the Son effected both these things, being the Word of God, descending from the Father, becoming incarnate, stooping low, even to death, and consummating the arranged plan of our salvation, upon whom [Paul], exhorting us unhesitatingly to believe, again says, "Who shall ascend into heaven? that is, to bring down Christ; or who shall descend into the deep? that is, to liberate Christ again from the dead." Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg.446

But Eve was disobedient; for she did not obey when as yet she was a virgin. And even as she, having indeed a husband, Adam, but being nevertheless as yet a virgin (for in Paradise "they were both naked, and were not ashamed," inasmuch as they, having been created a short time previously, had no understanding of the procreation of children: for it was necessary that they should first come to adult age, and then multiply from that time onward), having become disobedient, was made the cause of death, both to herself and to the entire human race. Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg. 455

By means of the second man did He bind the strong man, and spoiled his goods, and abolished death, vivifying that man who had been in a state of death. For at the first Adam became a vessel in his (Satan's) possession, whom he did also hold under his power, that is, by bringing sin on him iniquitously, and under color of immortality entailing death upon him. For, while promising that they should be as gods, which was in no way possible for him to be, he wrought death in them: wherefore he who had led man captive, was justly captured in his turn by God; but man, who had been led captive, was loosed from the bonds of condemnation. Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg.456

For [Adam] showed his repentance by his conduct, through means of the girdle [which he used], covering himself with fig-leaves, while there were many other leaves, which would have irritated his body in a less degree. He, however, adopted a dress conformable to his disobedience, being awed by the fear of God; and resisting the erring, the lustful propensity of his flesh. Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg.456

Inasmuch as, he says, I have by disobedience lost that robe of sanctity which I had from the Spirit, I do now also acknowledge that I am deserving of a covering of this nature, which affords no gratification, but which gnaws have retained this clothing for ever, thus humbling himself, if God, who is merciful, had not clothed them with tunics of skins instead of fig-leaves. For this purpose, too, He interrogates them, that the blame might light upon the woman; and again, He interrogates her, that she might convey the blame to the serpent. For she related what had occurred. "The serpent," says she, "beguiled me, and I did eat." But He put no question to the serpent; for He knew that he had been the prime mover in the guilty deed; but He pronounced the curse upon him in the first instance, that it might fall upon man with a mitigated rebuke. For God detested him who had led man astray, but by degrees, and little by little, He showed compassion to him who had been beguiled. Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg. 457

Wherefore also He drove him out of Paradise, and removed him far from the tree of life, not because He envied him the tree of life, as some venture to assert, but because He pitied him, [and did not desire] that he should continue a sinner for ever, nor that the sin which surrounded him should be immortal, and evil interminable and irremediable. But He set a bound to his [state of] sin, by interposing death, and thus causing sin to cease, putting an end to it by the dissolution of the flesh, which should take place in the earth, so that man, ceasing at length to live to sin, and dying to it, might begin to live to God. Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg.457

In the first place, then, in the garden of God he disputed about God, as if God was not there, for he was ignorant of the greatness of God; and then, in the next place, after he had learned from the woman that God had said that they should die if they tasted the aforesaid tree, opening his mouth, he uttered the third falsehood, "You shall not die by death." But that God was true, and the serpent a liar, was proved by the result, death having passed upon them who had eaten. For along with the fruit they did also fall under the power of death, because they did eat in disobedience; and disobedience to God entails death. Wherefore, as they became forfeit to death, from that [moment] they were handed over to it. Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg.551

For man had been made a middle nature, neither wholly mortal, nor altogether immortal, but capable of either; so also the place, Paradise, was made in respect of beauty intermediate between earth and heaven. And by the expression, "till it," no other kind of labor is implied than the observance of God's command, lest, disobeying, he should destroy himself, as indeed he did destroy himself, by sin. Theophilus (A.D. 180) Ante-Nicene Fathers vol.2 pg.104

And God showed great kindness to man in this, that He did not suffer him to remain in sin for ever; but, as it were, by a kind of banishment, cast him out of Paradise, in order that, having by punishment expiated, within an appointed time, the sin, and having been disciplined, he should afterwards be restored. Theophilus (A.D. 180) Ante-Nicene Fathers vol.2 pg.104