Galatians 2:21, "I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain."The Old Testament Law has been fulfilled by Christ, our Lord. (See Galatians 4 and Colossians 2) There are some who teach the OT Tithe using Malachi 3:8, yet the also fail to inform you that the book of Malachi is actually not even written to the people, it is written to the Levite Priests!
Ephesians 2:8-9, " 8For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:9Not of works, lest any man should boast."
Malachi 2:1-2, "1And now, O ye priests, this commandment is for you.I highly recommend for you to read the entire book of Malachi, it doesn't take long and it is easy to understand who God is talking to and what He is angry about.
2If ye will not hear, and if ye will not lay it to heart, to give glory unto my name, saith the LORD of hosts, I will even send a curse upon you, and I will curse your blessings: yea, I have cursed them already, because ye do not lay it to heart."
Galatians 3:10-25 10"For as many as are of the works of the law are under the curse: for it is written, Cursed is every one that continueth not in all things which are written in the book of the law to do them.In Hebrews chapter 7 we are taught about the relationship Abraham had with Melchisedec in regards to him being his priest and the one in whom he gave tithes to.
11But that no man is justified by the law in the sight of God, it is evident: for, The just shall live by faith. 12And the law is not of faith: but, The man that doeth them shall live in them. 13Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree:
14That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith. 15Brethren, I speak after the manner of men; Though it be but a man's covenant, yet if it be confirmed, no man disannulleth, or addeth thereto.
16Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ. 17And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
18For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise. 19Wherefore then serveth the law? It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator.
20Now a mediator is not a mediator of one, but God is one.
21Is the law then against the promises of God? God forbid: for if there had been a law given which could have given life, verily righteousness should have been by the law. 22But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.
23But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed.
24Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. 25But after that faith is come, we are no longer under a schoolmaster."
Hebrews 7:1-28 "For this Melchisedec, king of Salem, priest of the most high God, who met Abraham returning from the slaughter of the kings, and blessed him; 2To whom also Abraham gave a tenth part of all; first being by interpretation King of righteousness, and after that also King of Salem, which is, King of peace;Jesus Christ is our High Priest, of whom we give ourselves to. He has no need of tithes. He and His Apostles and disciples taught, very clearly, How to Give in The New Testament.
3Without father, without mother, without descent, having neither beginning of days, nor end of life; but made like unto the Son of God; abideth a priest continually. 4Now consider how great this man was, unto whom even the patriarch Abraham gave the tenth of the spoils.
5And verily they that are of the sons of Levi, who receive the office of the priesthood, have a commandment to take tithes of the people according to the law, that is, of their brethren, though they come out of the loins of Abraham: 6But he whose descent is not counted from them received tithes of Abraham, and blessed him that had the promises. 7And without all contradiction the less is blessed of the better.
8And here men that die receive tithes; but there he receiveth them, of whom it is witnessed that he liveth. 9And as I may so say, Levi also, who receiveth tithes, payed tithes in Abraham. 10For he was yet in the loins of his father, when Melchisedec met him.
11If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need was there that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron?
12For the priesthood being changed, there is made of necessity a change also of the law. 13For he of whom these things are spoken pertaineth to another tribe, of which no man gave attendance at the altar. 14For it is evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning priesthood.
15And it is yet far more evident: for that after the similitude of Melchisedec there ariseth another priest, 16Who is made, not after the law of a carnal commandment, but after the power of an endless life.
17For he testifieth, Thou art a priest for ever after the order of Melchisedec. 18For there is verily a disannulling of the commandment going before for the weakness and unprofitableness thereof.
19For the law made nothing perfect, but the bringing in of a better hope did; by the which we draw nigh unto God. 20And inasmuch as not without an oath he was made priest: 21(For those priests were made without an oath; but this with an oath by him that said unto him, The Lord sware and will not repent, Thou art a priest for ever after the order of Melchisedec:)
22By so much was Jesus made a surety of a better testament. 23And they truly were many priests, because they were not suffered to continue by reason of death: 24But this man, because he continueth ever, hath an unchangeable priesthood.
25Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them. 26For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens;
27Who needeth not daily, as those high priests, to offer up sacrifice, first for his own sins, and then for the people's: for this he did once, when he offered up himself. 28For the law maketh men high priests which have infirmity; but the word of the oath, which was since the law, maketh the Son, who is consecrated for evermore."