The resurrection of the dead was also captured through a harvest motif. This was a time of separation to indicate the true sons of God, ones born of the Spirit and not those who laid claims to their physical lineage as Jews.
Jesus explained through a parable.
Matthew 13:38-40 KJV
The field is the world; the good seed are the children of the kingdom; but the tares are the children of the wicked one ;  The enemy that sowed them is the devil; the harvest is the end of the world; and the reapers are the angels.  As therefore the tares are gathered and burned in the fire; so shall it be in the end of THIS world.
This is better captured in the Youngs Literal translation which is closer to the Greek.
36 Then having let away the multitudes, Jesus came to the house, and his disciples came near to him, saying, `Explain to us the simile of the darnel of the field.’
37 And he answering said to them, `He who is sowing the good seed is the Son of Man,
38 and the field is the world, and the good seed, these are the sons of the reign, and the darnel are the sons of the evil one,
39 and the enemy who sowed them is the devil, and the harvest is a full end of the age, and the reapers are messengers.
40 `As, then, the darnel is gathered up, and is burned with fire, so shall it be in the full end of THIS age.
So in the book of Revelation John sees this in a vision.
Revelation 14:14-16 KJV
And I looked, and behold a white cloud, and upon the cloud one 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, 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.  And he that sat on the cloud thrust in his sickle on the earth; and the earth was reaped.
So when was this to happen? 2,000 years later? No.
Revelation 1:1 KJV
The Revelation of Jesus Christ, which God gave unto him, to shew unto his servants things which must SHORTLY come to pass; and he sent and signified it by his angel unto his servant John:
This echoed the prophecy of Daniel that the resurrection was to happen at the time of the end and not the end of time. The end of the Mosaic age.
Daniel 12:1-4 KJV
And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book.  And many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt.  And they that be wise shall shine as the brightness of the firmament; and they that turn many to righteousness as the stars for ever and ever.  But thou, O Daniel, shut up the words, and seal the book, even to the time of the end: many shall run to and fro, and knowledge shall be increased.
Daniel 12:8-9 KJV
And I heard, but I understood not: then said I, O my Lord, what shall be the end of these things ?  And he said, Go thy way, Daniel: for the words are closed up and sealed till the time of the end.
Daniel 12:13 KJV
But go thou thy way till the end be : for thou shalt rest, and stand in thy lot at the end of the days.
This is why when Paul to the church at Thessalonica to encourage them in the severe persecution that they were going through of a hope that was to be fulfilled in their time.
But we do not want you to be uninformed, brethren, about those who are asleep, so that you will not grieve as do the rest who have no hope. For if we believe that Jesus died and rose again, even so God will bring with Him those who have fallen asleep in Jesus. For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord, will not precede those who have fallen asleep.
For the Lord Himself will descend from heaven with a shout, with the voice of the archangel and with the trumpet of God, and the dead in Christ will rise first. Then we who are alive and remain will be caught up together with them in the clouds to meet the Lord in the air, and so we shall always be with the Lord. Therefore comfort one another with these words. – 1 Thessalonians 4:13-18
The righteous no longer sleep in the grave. They now reside in the presence of the Lord. Jesus is the resurrection in us. It is no longer a promise but a present reality.