An excerpt on firstfruits from: There Is No Such Thing as a Conservative-Republican Christian: Jesus is a small-c communist:

Giving your firstfruits means giving to this, God's, cause before you literally give to anything else (especially toward yourself for your personal upkeep or pleasure or the upkeep or pleasure of those who love you). Jesus explained. For if ye love them which love you, what reward have ye? do not even the publicans the same? (Matthew 5:46). The publicans were tax collectors who took their cut from what they forcibly collected for the sake of the greedy Empire that didn't take care of the poor. What reward for that behavior could those unrepentant tax collectors expect from God? Your firstfruits belong to God. Really, all your fruits are God's if you can grasp it. It means your first obligation is to give and share not for recompense. It means, as we have shown elsewhere in this work, one is to give in a way that is conducive to everyone learning to give and share all first and foremost with those with the least. Rewards that are not conducive to giving and sharing all first and foremost with those with the least reinforce the pattern of giving for the sake of getting. That reinforces the pattern of behavior of giving to those with the means to give directly back or for the sake of the ego being massaged by the people to whom one gives. It is the vain reinforcement of being lauded by fellow humans as a humanitarian or philanthropist. Those are not the reasons God gives us life and provisioning. They are not Christlike motives. Also, where are such friends once the money has run out?

Therefore when thou doest thine alms, do not sound a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward. (Matthew 6:2).

It perpetuates wrong motives and results that fall miserably short of what it takes to solve the problem of the poor. Giving to those who already love us does not show the way to them that it is better to give than to receive. It is better that they too give all and share all for the sake of the poor and wanting in body and spirit. That is the solution: The right spirit.

This teaching is completely consistent with Jesus's way of spreading that purest and most abundant spirit of love he showed in going to the cross.

Now, none of this is to say that in the case where one gives all to the poor, who cannot repay the giver in kind, and people give to that giver and say good things about that giver, it is an ungodly reward. The original intention was not designed for selfish reward. In addition, anyone who gives discreetly to the poor will continue to give in that discreet manner from what is entrusted to him or her by others who learn of such good deeds that glorify God. This is how the Apostles were.

Teach this and do this and you will be keeping Jesus's commandment as he said, Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven. (Matthew 5:16). You see the difference. One form of giving is vain and egotistical. The other gives all credit to God. The first is utter failure. The latter is the solution since all are all together in God. The first remains self-centered. The first gives to gain for self. The latter is unselfish. The latter gives completely for the sake of others. The results of such teaching and giving and sharing will be the light to the people. Such results are literally the results of God. It is the work of God.

Really, as Jesus made clear by implication with his statement about being perfect by giving your all for the poor, all your fruits belong to God. Do with less yourself, meaning deny yourself, so that you may give and share. God will reward you openly for your earnestly having put others first in secret. It is Christlike so to do.