"the main harvest in Revelation 14 is Jewish that's why they're connected to grapes"
The grape harvest is doomed to wrath of God, they cannot be messianic Jewry. You know in Ephesians it says between jew and gentile there is no division if they are saved, the dividing wall. the enmity is broken down, they are all of one now.
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Ephesians 2
14 For He Himself is our peace, who has made both one, and has broken down the middle wall of separation, 15 having abolished in His flesh the enmity,
that is, the law of commandments
contained in ordinances, so as to create in Himself one new man
from the two,
thus making peace, 16 and that He might reconcile them both to God in one body through the cross,
thereby putting to death the enmity. 17 And He came and preached peace to you who were afar off and to those who were near. 18 For through Him we both have access by one Spirit to the Father.
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As far as the first sickle, the saints God has given into the hands of Satan for a season of time, many will be killed.
God did that, and it is why it is God's sickle reaping the harvest of the earth, they are killed by the beast , they were given into the hands of the little horn by God to be killed, until the time came for them to inherit the earth.
Daniel 7
21 “I was watching; and the same horn
was making war against the saints, and prevailing against them, 22 until the Ancient of Days came, and a judgment was made
in favor of the saints of the Most High, and the time came for the saints to possess the kingdom.
23 “Thus he said:
‘The fourth beast shall be
A fourth kingdom on earth,
Which shall be different from all
other kingdoms,
And shall devour the whole earth,
Trample it and break it in pieces.
24 The ten horns
are ten kings
Who shall arise from this kingdom.
And another shall rise after them;
He shall be different from the first
ones,
And shall subdue three kings.
25 He shall speak
pompous words against the Most High,
Shall persecute[
j] the saints of the Most High,
And shall intend to change times and law.
Then the saints shall be given into his hand
For a time and times and half a time.
26 , the people of God will inherit the earth
‘But the court shall be seated,
And they shall take away his dominion,
To consume and destroy it forever.
27 Then the kingdom and dominion,
And the greatness of the kingdoms under the whole heaven,
Shall be given to the people, the saints of the Most High.
His kingdom is an everlasting kingdom,
And all dominions shall serve and obey Him.’