That same Jesus also claimed that He would come again (John 14:3; Matthew 16:27–28).
Yes, he did. What is important is how the second coming would occur and be known:
Mat 24:27
For as the lightning comes from the east and shines as far as the west, so will be the coming of the Son of Man.
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Mat 24:30 Then will appear in heaven the sign of the Son of Man, and then
all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of heaven with power and great glory.
Mat 24:31 And he will send out his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of heaven to the other.
Act 1:9 And when he had said these things, as they were looking on,
he was lifted up, and a cloud took him out of their sight.
Act 1:10 And while they were gazing into heaven as he went, behold, two men stood by them in white robes,
Act 1:11 and said, “Men of Galilee, why do you stand looking into heaven?
This Jesus, who was taken up from you into heaven, will come in the same way as you saw him go into heaven.”
1Co 15:22 For as in Adam all die, so also in Christ shall all be made alive.
1Co 15:23 But each in his own order: Christ the firstfruits,
then at his coming those who belong to Christ.
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1Co 15:42 So is it with the resurrection of the dead.
What is sown is perishable; what is raised is imperishable.
1Co 15:43 It is sown in dishonor; it is raised in glory. It is sown in weakness; it is raised in power.
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1Co 15:50 I tell you this, brothers:
flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable.
1Co 15:51 Behold! I tell you a mystery.
We shall not all sleep, but we shall all be changed,
1Co 15:52 in a moment,
in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised imperishable, and we shall be changed.
1Co 15:53
For this perishable body must put on the imperishable, and this mortal body must put on immortality.
1Th 4:14 For since we believe that Jesus died and rose again, even so, through Jesus,
God will bring with him those who have fallen asleep.
1Th 4:15 For this we declare to you by a word from the Lord,
that we who are alive, who are left until the coming of the Lord, will not precede those who have fallen asleep.
1Th 4:16 For
the Lord himself will descend from heaven with a cry of command, with the voice of an archangel, and with the sound of the trumpet of God. And the dead in Christ will rise first.
1Th 4:17
Then we who are alive, who are left, will be caught up together with them in the clouds to meet the Lord in the air, and so we will always be with the Lord.
Very clearly none of this has happened. These are very visible signs of the physical return of Christ, visible to all in the world at the same time, both believers and unbelievers. We are physically still perishable and mortal; we still die and the dead have not been raised. We have not, and no one has, been caught up together with the dead in Christ to meet Christ in the clouds as he descends.
2Pe 3:4 They will say, “
Where is the promise of his coming? For ever since the fathers fell asleep, all things are continuing as they were from the beginning of creation.”
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2Pe 3:9 The Lord is not slow to fulfill his promise as some count slowness, but is patient toward you, not wishing that any should perish, but that all should reach repentance.
2Pe 3:10 But
the day of the Lord will come like a thief, and then the heavens will pass away with a roar, and the heavenly bodies will be burned up and dissolved, and the earth and the works that are done on it will be exposed.
2Pe 3:11 Since all these things are thus to be dissolved, what sort of people ought you to be in lives of holiness and godliness,
2Pe 3:12
waiting for and hastening the coming of the day of God, because of which the heavens will be set on fire and dissolved, and the heavenly bodies will melt as they burn!
1Jn 2:18 Children, it is the last hour, and as you have heard that antichrist is coming, so now many antichrists have come. Therefore
we know that it is the last hour.
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1Jn 2:28 And now, little children, abide in him,
so that when he appears we may have confidence and not shrink from him in shame
at his coming.
1Jn 3:2 Beloved, we are God's children now, and
what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is.
1Jn 5:19 We know that we are from God, and
the whole world lies in the power of the evil one.
None of the apostles thought Jesus had returned in their time. This is most important concerning John, given that 1 John was likely written between 85-95 A.D. Together with the earlier letters by Paul and Peter, which give us signs of the return of Jesus, none of which have happened, it is impossible that Jesus has already returned.