I really don't understand this first fruits thing any more than you do, but it seems like some good meditation. I think about Proverbs which says to honor God with the first fruits, and i think about Paul saying to present our bodies as a living sacrifice. I think about how the Lord says that a seed falls to the ground and dies, it abides alone, yet it produces much fruit. I think about the fruit of the spirit which is love, joy, peace, longsuffering, truth, ect
Proverbs 3:9 Honor the Lord with your possessions,
And with the firstfruits of all your increase;
James 1:2 My brethren, count it all joy when you fall into various trials, 3 knowing that the testing of your faith produces patience.
9 Let the lowly brother glory in his exaltation, 10 but the rich in his humiliation, because as a flower of the field he will pass away. 11 For no sooner has the sun risen with a burning heat than it withers the grass; its flower falls, and its beautiful appearance perishes. So the rich man also will fade away in his pursuits.
18 Of His own will He brought us forth by the word of truth, that we might be a kind of firstfruits of His creatures.
Romans 8:21 because the creation itself also will be delivered from the bondage of corruption into the glorious liberty of the children of God. 22 For we know that the whole creation groans and labors with birth pangs together until now. 23 Not only that, but we also who have the firstfruits of the Spirit, even we ourselves groan within ourselves, eagerly waiting for the adoption, the redemption of our body.
8 And we know that all things work together for good to those who love God, to those who are the called according to His purpose. 29 For whom He foreknew, He also predestined to be conformed to the image of His Son, that He might be the firstborn among many brethren. 30 Moreover whom He predestined, these He also called; whom He called, these He also justified; and whom He justified, these He also glorified.
Galatians 5:22 But the fruit of the Spirit is love, joy, peace, longsuffering, kindness, goodness, faithfulness, 23 gentleness, self-control. Against such there is no law.
Ephesians 5:9 (for the fruit of the Spirit[a] is in all goodness, righteousness, and truth),