Jesus says some things indicating that the time of the judgement was unknown, as for example, “But about that day or hour no one knows, neither the angels in heaven, nor the Son, but only the Father.” And if it is completely unknown, then it would be reasonable to say that it could not be known whether it is long or short. But he also says things, such as those already mentioned, that suggest a short time. In fact, this was true from the beginning of his ministry. Mark describes this:

Now after John was arrested, Jesus came to Galilee, proclaiming the good news of God, and saying, “The time is fulfilled, and the kingdom of God has come near; repent, and believe in the good news.”

Since Daniel 7 says that “his dominion is an everlasting dominion that shall not pass away, and his kingship is one that shall never be destroyed,” it was natural for people to understand from Christ’s preaching that the end of the world was at hand in a literal sense. This does not mean that there cannot be a reasonable understanding of this for Christians living in the present day. But there can be no reasonable doubt that the early Christians in fact held such a belief about the nearness of the end, and that they held this belief on account of this kind of preaching. 

Thus for example when St. John says, “Children, it is the last hour! As you have heard that antichrist is coming, so now many antichrists have come. From this we know that it is the last hour,” his words may be explained in a general sense. But it does not make sense for him to actually say this in this particular way, unless he believes that a very short time remains until the end of the world. In other words, we knew that antichrists would come and then the world would end; and now the antichrists have come; so the world must be about to end.

The second letter of Peter, however, warns against assuming that the end must come quickly:

But do not ignore this one fact, beloved, that with the Lord one day is like a thousand years, and a thousand years are like one day. The Lord is not slow about his promise, as some think of slowness, but is patient with you, not wanting any to perish, but all to come to repentance. But the day of the Lord will come like a thief, and then the heavens will pass away with a loud noise, and the elements will be dissolved with fire, and the earth and everything that is done on it will be disclosed.

Since all these things are to be dissolved in this way, what sort of persons ought you to be in leading lives of holiness and godliness, waiting for and hastening the coming of the day of God, because of which the heavens will be set ablaze and dissolved, and the elements will melt with fire? But, in accordance with his promise, we wait for new heavens and a new earth, where righteousness is at home.

Daniel Wallace says, “From one perspective, this short epistle is the most disputed book in the NT canon as to authenticity. From another, the issue of authorship is already settled, at least negatively: the apostle Peter did not write this letter.” By “most disputed book,” he means that the most doubt is put on the question of whether it is actually written by the author to whom it is attributed. He believes himself that St. Peter wrote it, but says that the majority of scholars have already concluded that he did not. Although they have various reasons for their opinion, one of the reasons is the idea that it was written after it was already clear that Christ was not returning soon.

Regardless of how the question of authorship is resolved, this argument is probably unnecessary. Even if the letter was written by St. Peter himself in the 60s, it would have already been 30 years since the time of Christ, and it would already be becoming clear that there was a need to correct people’s idea of the end of the world. The Gospels themselves do something similar. For example, immediately after, “Truly I tell you, there are some standing here who will not taste death before they see the Son of Man coming in his kingdom,” Matthew continues, “Six days later, Jesus took with him Peter and James and his brother John and led them up a high mountain, by themselves,” and goes on to give the account of the Transfiguration. By this means he at least suggests, although without saying so explicitly, that the words of Christ were fulfilled in the vision of the apostles at the time.