It helps greatly to define "the end" as God has defined it. Too many people are assuming that the "end" means the end of time, or the end of the material natural world. That is false doctrine. We have to abide by God's word, and it originates from the OT usage.
There have been several "ends" that have resulted from a day of the Lord, which was God's way of saying He was coming to judge the wicked and destroy a nation or people.
In Noah's day, the "end" was the end of all flesh.
"And God said to Noah, `An end of all flesh hath come before Me, for the earth hath been full of violence from their presence; and lo, I am destroying them with the earth." (Gen. 6:13, YLT)
Of which Peter said,
"Whereby the world that then was, being overflowed with water, perished:" (2 Pet. 3:6, KJV)
What was the end of Noah's flood? What "world" perished? Was the physical material world gone? The end was the end of all living flesh that did not board the ark with Noah. They died not believing the word of God which Noah had preached. While the contours and shape of the earth was altered, the physical natural world remained.
We must define the "end" from the specific prophesy of that specific day of judgment called the day of the Lord. There have been many days of judgment, called the day of the Lord, or sometimes the day of wrath, or the day of their calamity (Job 21:30).
"A day of wrath [is] that day, A day of adversity and distress, A day of waste and desolation, A day of darkness and gloominess, A day of cloud and thick darkness." (Zeph. 1:15, YLT)
"3 And what do ye at a day of inspection? And at desolation? -- from afar it cometh. Near whom do ye flee for help? And where do ye leave your honour?" (Isa. 10:3, YLT)
A day of inspection was a day of desolation.
"For this is the day of the Lord God of hosts, a day of vengeance, that he may avenge him of his adversaries: and the sword shall devour, and it shall be satiate and made drunk with their blood: for the Lord God of hosts hath a sacrifice in the north country by the river Euphrates." (Jer. 46:10, KJV)
A day of the Lord was a time when God judged a nation and the wicked people who had filled up His wrath. There are many such judgment days spoken of in the OT. We must determine which day of judgment is being discussed.
"7 so that ye are not behind in any gift, waiting for the revelation of our Lord Jesus Christ, 8 who also shall confirm you unto the end -- unblamable in the day of our Lord Jesus Christ;" (1 Cor. 1:7-8, YLT)
The two verses equate "the day of our Lord Jesus Christ" with "the revelation of our Lord Jesus Christ". They were the same day, the same judgment; and that judgment was what Jesus pronounced during His ministry to those Jews who heard Him in the 1st century AD.... pronounced upon Jerusalem.
"37 O Jerusalem, Jerusalem, thou that killest the prophets, and stonest them which are sent unto thee, how often would I have gathered thy children together, even as a hen gathereth her chickens under her wings, and ye would not! 38 Behold, your house is left unto you desolate." (Matt. 23:37-38, KJV)
Christ told them it was Jerusalem that was going to be judged. He told them repeatedly that He was coming back to judge those who killed His prophets, and wise men.
"20 And when ye shall see Jerusalem compassed with armies, then know that the desolation thereof is nigh.
21 Then let them which are in Judaea flee to the mountains; and let them which are in the midst of it depart out; and let not them that are in the countries enter thereinto.
22 For these be the days of vengeance, that all things which are written may be fulfilled." (Luke 21:20-22, KJV)
Luke made it very clear that the Olivet discourse was discussing the judgment to come upon Jerusalem and all Judea. In the same chapter discussing the destruction of the temple in Jerusalem the judgment day was pronounced. Christ told them repeatedly that Jerusalem was going to be destroyed.
John the baptizer, speaking to that generation of vipers, to the scribes and Pharisees,
"10 And now also the axe is laid unto the root of the trees..." (Matt. 3:10, KJV)
Jesus speaking to those same vipers,
"35 That upon you may come all the righteous blood shed upon the earth, from the blood of righteous Abel unto the blood of Zacharias son of Barachias, whom ye slew between the temple and the altar. 36 Verily I say unto you, All these things shall come upon this generation." (Matt. 23:35-36, KJV)
It was that generation of the 1st century AD, that generation of unbelieving scribes and Pharisees that the judgment was pronounced. They rejected the promised Messiah, crucifying Him, and killed the disciples and Apostles He had sent to them. John's warning to those people was the day of judgment coming upon them. Christ's warnings were the day of judgment coming upon them... in the 1st century AD.
So, when Paul and Peter and others spoke of "the end" it was referring to the end of the temple in Jerusalem and the end of the Mosaic covenant with those of that age. Daniel had asked when shall be the end. The messenger (Christ) answered:
" ...and at the completion of the scattering of the power of the holy people, finished are all these.'" (Dan. 12:7, YLT)
Discussing the sacrifices at the temple, the end was defined as the time the temple would be destroyed in Jerusalem, and the holy people - Daniel's holy people - the Jews' power would be scattered. This was the same end which Christ referenced in Matt. 24:15, linking the destruction of the temple to the judgment prophesy of Daniel.
The end of the 1st century NT scriptures was discussing the end of the Mosaic covenant and that animal sacrificial temple in Jerusalem. So, 1 Cor. 1:8 referred to the end of the temple in Jerusalem. Just as Paul stated two chapters later,
"11 And all these things as types did happen to those persons, and they were written for our admonition, to whom the end of the ages did come," (1 Cor. 10:11, YLT)
that the end of the ages had come upon them... that generation in which Paul said it. That end was the day the temple in Jerusalem was destroyed, reportedly the 9th-10th of Av in AD 70. They were waiting for it, just as Christ had told them to watch for it, and to flee to the mountains when they saw it happening (Matt. 24:16).
The Bible never speaks of the end of time, nor the end of the natural physical world. Even 2 Pet. 3:12 which is couched in Hebraic metaphors recalls the promise of God from both Ezekiel and Jeremiah to gather the Jews into Jerusalem and melt them there.
"19 Therefore thus saith the Lord God; Because ye are all become dross, behold, therefore I will gather you into the midst of Jerusalem. 20 As they gather silver, and brass, and iron, and lead, and tin, into the midst of the furnace, to blow the fire upon it, to melt it; so will I gather you in mine anger and in my fury, and I will leave you there, and melt you." (Ezek. 22:19-20, KJV)
We are on the other side of that event, and we are not waiting for Jesus to return to judge Jerusalem and destroy the temple again. As our High Priest, and Savior, He judges the nations, and the people daily.
Much more on this at my blog: ShreddingTheVeil in the posts:
The Fig Tree and The Mountain - here
The Signs of the Feasts - Part II: Christ Told His Disciples When He Would Return - here
The Signs of Revelation - Part I: The Time of His Coming - here