Comparing one sentence of Jesus while on earth (at the end of Matthew’s gospel) with one sentence of the risen Christ (at the end of the Revelation of Christ to John) requires appreciating the significance of time, location and divine prerogative. I do not intend to delve into all of that. I would simply say that the felt need to reconcile only occurs with us earth-bound mortals who are trying to grasp eternal verities. And I would suggest that the 14th chapter of Revelation reveals something of the matter of when God provides knowledge of the timing of Christ’s ‘coming’, which Jesus referred to both at the end of Matthew’s gospel account and of the Revelation Jesus gave to John.
The preamble to this is that Jesus said in many of his parables that he would go away for a long time (to a far country – heaven) before suddenly returning, like a thief in the night, and “at an hour you do not think”. Matthew’s gospel adds, “And he shall gather his wheat into the garner,” “Gather the wheat into my barn,” and “The harvest is the end of the world” – Matthew 24:44; 3:12; 13:30 & 13:39. Immediately before he appears to start the day of resurrection and judgment, his own (the good wheat) will have been safely harvested by him. Then, in Revelation 14 the risen Christ provides more details about that:
“And I [John] looked, and behold a white cloud, and upon the cloud sat
like unto the Son of man, having on his head a golden crown, and in
his hand a sharp sickle. And another angel came out of the temple [in
heaven], crying with a loud voice to him that sat on the cloud, Thrust
in thy sickle, and reap: for the time is come for thee to reap; for
the harvest of the earth is ripe.” (vss. 14-15)
Then another harvest is detailed by another angel who comes from the altar [in heaven], another sickle being used by an angel to gather the vine of the earth, to cast it into the massive winepress of the wrath of God. Now, here is an expository quote:
“An angel commands the Son to reap, Revelation 14:14. This seems to
present a difficulty… ‘And he that sat on the cloud thrust in his
sickle on the earth; and the earth was reaped’ [vs. 16]. Yes, but who
or what was a created angel to command one like unto the Son of man?
[Then quotes Hebrews 1:4, 6 & 2:9 to show Christ’s superiority to
angels.] “Nevertheless, risen, he is crowned with glory and honour,
and the passage in Revelation 14:15 shows him to be head over all. How
then shall an angel command him? This is resolved by observing that
just as the reference in Hebrews 2:9 was qualified by that in Hebrews
1:6, so the scripture ‘Of that day’ – the same day as ‘the day of
reaping’ in Revelation 14:15 – ‘knoweth no man, no, not the angels
which are in heaven, neither the Son, but the Father’, Mark 13:32.
Hence the Father sent the angel – who was but his messenger – out of
his holy temple to convey the Father’s long awaited commandment to one
like unto the Son of man: ‘Thrust in thy sickle, and reap’, Revelation
14:15.” [“The Revelation of Jesus Christ”, pp. 405-406, John Metcalfe]
The book then explains how a distinct angel of judgment comes from the altar (in heaven), after ‘the earth was reaped’. The Son of man reaps the firstfruits once God sends an angel to tell him to reap. Yet the second reaping, of the vine of the earth with its ripe grapes, follows instantly, by an angel.
“This implies that the wheat harvest, as opposed to the gathering of
the grapes of the vine of the earth, is an entirely separate event:
the two representing as different a form in agriculture, as do the
sheep and the goats in nature. Therefore the appearance of another
angel having a sharp sickle in his hand, cannot possibly be in respect
of that harvest of the firstfruits already reaped by one like unto the
Son of man, though the gathering of the grapes follows instantly…
Revelation 14:19, again, this is an old testament figure. But what
does it signify? It is a figure of the resurrection of damnation in
the day of judgment.” [Ibid. pp. 407 & 409]
This is where Acts 17:31 completes the picture. God has appointed the day in which he will judge the world in righteousness by the one he raised from the dead – Jesus Christ. The Father’s prerogative is to appoint that day of judgment, which is also the day of the resurrection of the dead, but Christ knows (and has always known) that he comes for his own immediately before the grapes of wrath are gathered. Only the saints see the Son when he comes for them. The inhabitants of the earth ‘see’ only the sickle of judgment swiping them up and into the winepress of the wrath of God. They have been caught unawares as with a thief coming in the night. That is why the Revelation depicts God commanding an angel to tell the Son when to gather the firstfuits, for there will be no time lapse between that and the judgment on the ‘weeds’ as opposed to gathering the good wheat. One event will follow on from the other immediately. Hence the imminent aspect of the whole end-time scenario. Jesus knew there would be a long time (humanly speaking) between his return to heaven and coming to gather his own, then to immediately judge the wicked. He told his own to be always ready, in case he should return in their life-time, but from the standpoint of eternity, a couple of thousand years is only a couple of days. He will come soon enough, but not a moment too soon, for it is the Father’s prerogative to state when, exactly, those rapid events will explode.
This does not imply any inferiority on the part of the Son, only total co-operation and harmony. One person in the Godhead never infringes on the responsibilities of the other two persons, but all three work in unity, together, as one. The prerogative of the Father is to give the command as to when a certain event will start, and the Son does it instantly God sends an angel to say “Reap!”.
Unfortunately, sinful human reasoning is that of a pyramid-like hierarchy – and that is why some see a dichotomy where there is none. Further, the correct translation of Revelation 22:12 is that Christ promises to come quickly, not ‘soon’, and scripture shows breath-taking swift and decisive action on that awesome day. The Greek word ‘tachu’ means ‘speedily’ (as shown in Young’s Analytical Concordance p. 790). Anyone checking its N.T. usage will see that it refers to rapid action, not an event soon to happen: Mat. 5:25; 8:7,8; Mk. 16:8; Jn. 11:29; Rev. 2:5, 16; 3:11; 11:14, 22:7, 12, 20. This shows there is nothing to reconcile between those two verses you ask about.