The Law of Moses required the offering of first fruits and tithes.
Exodus 23:19 The first of the firstfruits of thy land thou shalt bring into the house of the LORD thy God.
Leviticus 23:10 Speak unto the children of Israel, and say unto them, When ye be come into the land which I give unto you, and shall reap the harvest thereof, then ye shall bring a sheaf of the firstfruits of your harvest unto the priest: 11 And he shall wave the sheaf before the LORD, to be accepted for you: on the morrow after the sabbath the priest shall wave it. 12 And ye shall offer that day when ye wave the sheaf an he lamb without blemish of the first year for a burnt offering unto the LORD. 13 And the meat offering thereof shall be two tenth deals of fine flour mingled with oil, an offering made by fire unto the LORD for a sweet savour: and the drink offering thereof shall be of wine, the fourth part of an hin. 14 And ye shall eat neither bread, nor parched corn, nor green ears, until the selfsame day that ye have brought an offering unto your God: it shall be a statute for ever throughout your generations in all your dwellings.
Deuteronomy 20:1 And it shall be, when thou art come in unto the land which the LORD thy God giveth thee for an inheritance, and possessest it, and dwellest therein; 2 That thou shalt take of the first of all the fruit of the earth, which thou shalt bring of thy land that the LORD thy God giveth thee, and shalt put it in a basket, and shalt go unto the place which the LORD thy God shall choose to place his name there. 3 And thou shalt go unto the priest that shall be in those days, and say unto him, I profess this day unto the LORD thy God, that I am come unto the country which the LORD sware unto our fathers for to give us. 4 And the priest shall take the basket out of thine hand, and set it down before the altar of the LORD thy God. 5 And thou shalt speak and say before the LORD thy God, A Syrian ready to perish was my father, and he went down into Egypt, and sojourned there with a few, and became there a nation, great, mighty, and populous: 6 And the Egyptians evil entreated us, and afflicted us, and laid upon us hard bondage: 7 And when we cried unto the LORD God of our fathers, the LORD heard our voice, and looked on our affliction, and our labour, and our oppression: 8 And the LORD brought us forth out of Egypt with a mighty hand, and with an outstretched arm, and with great terribleness, and with signs, and with wonders: 9 And he hath brought us into this place, and hath given us this land, even a land that floweth with milk and honey. 10 And now, behold, I have brought the firstfruits of the land, which thou, O LORD, hast given me. And thou shalt set it before the LORD thy God, and worship before the LORD thy God: 11 And thou shalt rejoice in every good thing which the LORD thy God hath given unto thee, and unto thine house, thou, and the Levite, and the stranger that is among you.
12 When thou hast made an end of tithing all the tithes of thine increase the third year, which is the year of tithing, and hast given it unto the Levite, the stranger, the fatherless, and the widow, that they may eat within thy gates, and be filled; 13 Then thou shalt say before the LORD thy God, I have brought away the hallowed things out of mine house, and also have given them unto the Levite, and unto the stranger, to the fatherless, and to the widow, according to all thy commandments which thou hast commanded me: I have not transgressed thy commandments, neither have I forgotten them: 14 I have not eaten thereof in my mourning, neither have I taken away ought thereof for any unclean use, nor given ought thereof for the dead: but I have hearkened to the voice of the LORD my God, and have done according to all that thou hast commanded me. 15 Look down from thy holy habitation, from heaven, and bless thy people Israel, and the land which thou hast given us, as thou swarest unto our fathers, a land that floweth with milk and honey.
2 Chronicles 31:4 Moreover he (Hezekiah) commanded the people that dwelt in Jerusalem to give the portion of the priests and the Levites, that they might be encouraged in the law of the LORD.5 And as soon as the commandment came abroad, the children of Israel brought in abundance the firstfruits of corn, wine, and oil, and honey, and of all the increase of the field; and the tithe of all things brought they in abundantly. 6 And concerning the children of Israel and Judah, that dwelt in the cities of Judah, they also brought in the tithe of oxen and sheep, and the tithe of holy things which were consecrated unto the LORD their God, and laid them by heaps. 7 In the third month they began to lay the foundation of the heaps, and finished them in the seventh month.
Those who believe the gospel and are baptised into Jesus Christ are not under the Law of Moses. Therefore, the Law concerning first fruits and tithes is no longer in force. There is no priesthood to support, nor house of God to bring them to.
Paul makes it clear that we are not under the Law.
Galatians 4:21 Tell me, ye that desire to be under the law, do ye not hear the law? 22 For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman. 23 But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise. 24 Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Agar. 25 For this Agar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children. 26 But Jerusalem which is above is free, which is the mother of us all. 27 For it is written, Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not: for the desolate hath many more children than she which hath an husband. 28 Now we, brethren, as Isaac was, are the children of promise. 29 But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now. 30 Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman. 31 So then, brethren, we are not children of the bondwoman, but of the free.
Galatians 5:1 Stand fast therefore in the liberty wherewith Christ hath made us free, and be not entangled again with the yoke of bondage.
Justification is by faith, not by observing the Law of Moses.
Romans 3:28 Therefore we conclude that a man is justified by faith without the deeds of the law.
The counsel at Jerusalem decided
Acts 21:25 As touching the Gentiles which believe, we have written and concluded that they observe no such thing (i.e. the Law), save only that they keep themselves from things offered to idols, and from blood, and from strangled, and from fornication.
In Christ we are free to give to the service of the truth what we can afford.
2 Corinthians 8:12 For if there be first a willing mind, it is accepted according to that a man hath, and not according to that he hath not.
I hope this helps.