Irenaeus

In his own words on 2 Peter

• 2 Peter 2:19

  For as the serpent beguiled Eve, by promising her what he had not himself, so also do these men, by pretending [to possess] superior knowledge, and [to be acquainted with] ineffable mysteries; and, by promising that admittance which they speak of as taking place within the Pleroma, plunge those that believe them into death, rendering them apostates from Him who made them. And at that time, indeed, the apostate angel, having effected the disobedience of mankind by means of the serpent, imagined that he escaped the notice of the Lord; wherefore God assigned him the form and name [of a serpent]. But now, since the last times are [come upon us], evil is spread abroad among men, which not only renders them apostates, but by many machinations does [the devil] raise up blasphemers against the Creator, namely, by means of all the heretics already mentioned. For all these, although they issue forth from diverse regions, and promulgate different [opinions], do nevertheless concur in the same blasphemous design, wounding [men] unto death, by teaching blasphemy against God our Maker and Supporter, and derogating from the salvation of man.

  Against Heresies Book IV

• 2 Peter 3:8

  Now he died on the same day in which he did eat. For God said, "In that day on which ye shall eat of it, ye shall die by death." The Lord, therefore, recapitulating in Himself this day, underwent His sufferings upon the day preceding the Sabbath, that is, the sixth day of the creation, on which day man was created; thus granting him a second creation by means of His passion, which is that [creation] out of death. And there are some, again, who relegate the death of Adam to the thousandth year; for since "a day of the Lord is as a thousand years," he did not overstep the thousand years, but died within them, thus bearing out the sentence of his sin. Whether, therefore, with respect to disobedience, which is death; whether [we consider] that, on account of that, they were delivered over to death, and made debtors to it; whether with respect to [the fact that on] one and the same day on which they ate they also died (for it is one day of the creation); whether [we regard this point], that, with respect to this cycle of days, they died on the day in which they did also eat, that is, the day] of the preparation, which is termed "the pure supper," that is, the sixth day of the feast, which the Lord also exhibited when He suffered on that day; or whether [we reflect] that he (Adam) did not overstep the thousand years, but died within their limit,-it follows that, in regard to all these significations, God is indeed true. For they died who tasted of the tree; and the serpent is proved a liar and a murderer, as the Lord said of him: "For he is a murderer from the beginning, and the truth is not in him."

  Against Heresies Book 5

• 2 Peter 3:8

  For in as many days as this world was made, in so many thousand years shall it be concluded. And for this reason the Scripture says: "Thus the heaven and the earth were finished, and all their adornment. And God brought to a conclusion upon the sixth day the works that He had made; and God rested upon the seventh day from all His works." This is an account of the things formerly created, as also it is a prophecy of what is to come. For the day of the Lord is as a thousand years; and in six days created things were completed: it is evident, therefore, that they will come to an end at the sixth thousand year.

  Against Heresies Book 5