#3- Fourteen chapters into the book of Revelation we find John Speaking of the First-Fruits Remnant of Jewish Believers (see also Rev. 7 where they are defined as coming from the 12 tribes).

There can only be one time period called the FIRST-fruits. The first century.

James 1:1, 18,
James, a servant of God and of the Lord Jesus Christ,

To the twelve tribes (of Israel) in the Dispersion... Of his own will he brought US forth by the word of truth, that we should be a kind of FIRSTFRUITS of his creatures.

Revelation 14-

3and they were singing a new song before the throne and before the four living creatures and before the elders. No one could learn that song except the 144,000 who had been redeemed from the earth. 4It is these who have not defiled themselves with women, for they are chaste. It is these who follow the Lamb wherever he goes. These have been redeemed from mankind as FIRSTFRUITS for God and the Lamb...