Gal. 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."
Based on the above passage there are two covenants of worship that are taught in the scriptures. Now there are other covenants taught in the scriptures, but only two covenants of worship. The first covenant was given on Mt. Sinai to the children of Israel and was a covenant that gendered to bondage. At the time this scripture was written it answered to "Jerusalem which now is, and is in bondage with her children." This covenant is often called the "law." The second or new covenant is said to be free and to be the mother of us all. This covenant is often called the covenant of grace, or faith, or the kingdom of God.
The law covenant brought a curse upon those under the covenant. Gal. 3:10 "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. 11 But that no man is justified by the law in the sight of God, it is evident: for, the just shall live by faith." Since no one other than Jesus Christ has continued in all things which are written in the book of the law to do them, then everyone but Jesus Christ was under the curse of the law.
The following passages of scripture show us the purpose of the law covenant:
1. 1 Tim. 1:9 "Knowing this, that the law is not made for a righteous man, but for the lawless and disobedient, for the ungodly and for sinners, for unholy and profane, for murderers of fathers and murderers of mothers, for manslayers, 10 For whoremongers, for them that defile themselves with mankind, for menstealers, for liars, for perjured persons, and if there be any other thing that is contrary to sound doctrine."
2. Gal. 3:19 "Wherefore 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. 20 Now a mediator is not a mediator of one, but God is one. 21 Is 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. 22 But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe. 23 But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed. 24 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. 25 But after that faith is come, we are no longer under a schoolmaster. 26 For ye are all the children of God by faith in Christ Jesus."
3. Heb. 10:1 "For the law having a shadow of good things to come, and not the very image of the things, can never with those sacrifices which they offered year by year continually make the comers thereunto perfect. 2 For then would they not have ceased to be offered? because that the worshippers once purged should have had no more conscience of sins. 3 But in those sacrifices there is a remembrance again made of sins every year. 4 For it is not possible that the blood of bulls and of goats should take away sins."
From the above we see that the law was designed for the lawbreaker. It brought sins to remembrance, but it could not do away with sin. It also showed us the need for a redeemer. The law was simply a shadow of good things to come, but could make nothing perfect. The law was our schoolmaster to bring us unto Christ. The work of a schoolmaster is to bring the students to the school. The law taught us of the exceeding sinfulness of sin, and that we are sinners, and that we stood in need of a redeemer. The law as a schoolmaster pointed us to Christ. The law revealed to us that we were under the curse of the law of sin and death and unable to deliver ourselves out from under that curse.
The Lord came to fulfill the law. Matt. 5:17 "Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil. 18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled." The Lord kept the law to the jot and tittle and thus fulfilled the law. Christ completed the law and brought in everlasting righteousness for his people. Rom. 10:4, "For Christ is the end of the law for righteousness for every one that believeth." Christ completed the law for righteousness and according to 2 Cor. 5:21, "For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him." Through fulfilling the law and becoming sin for us he made us righteous. Also, Gal. 3:13 "Christ 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."
While the law has been fulfilled it still has benefit for us today in that it testifies to us of Jesus: John 5:39 "Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me." Also, the law gives us types and shadows of heavenly things: Heb. 10:1 "For the law having a shadow of good things to come…" and Col. 2:16 "Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the Sabbath days: which are a shadow of things to come; but the body is of Christ." In addition, the law gives us admonitions and examples for our edification and learning: 1 Cor. 10:6, "Now these things were our examples, to the intent we should not lust after evil things, as they also lusted." Notice 1 Cor. 10:11, "Now all these things happened unto them for ensamples: and they are written for our admonition, upon whom the ends of the world are come." Finally, the language of the New Testament is sprinkled with the events of the Old Testament. To understand the New Testament we need a real good working knowledge of the Old Testament. We, however, do not worship under the Old Covenant today.
The New Covenant came with the teaching and preaching of John the Baptist: Lk. 16:16 The law and the prophets were until John: since that time the kingdom of God is preached, and every man presseth into it. The Lord himself ushered in this New Testament: John 1:17 For the law was given by Moses, but grace and truth came by Jesus Christ."
The New Covenant is stated in Heb. 8: 6 But now hath he obtained a more excellent ministry, by how much also he is the mediator of a better covenant, which was established upon better promises. 7 For if that first covenant had been faultless, then should no place have been sought for the second. 8 For finding fault with them, he saith, Behold, the days come, saith the Lord, when I will make a new covenant with the house of Israel and with the house of Judah: 9 Not according to the covenant that I made with their fathers in the day when I took them by the hand to lead them out of the land of Egypt; because they continued not in my covenant, and I regarded them not, saith the Lord. 10 For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people: 11 And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest. 12 For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more."
The New Covenant is based on the principle of the new or spiritual birth where God writes his laws in the hearts and minds of his people, and not on 2 tables of stone. Furthermore, in the New Covenant there is no need to teach the people to know the Lord, for they all know him as a result of the new birth and the Lord's personal dealings with him. Now there is a lot that can be taught about the Lord and should be taught about the Lord, but we do not teach to know the Lord. Third, in this New Covenant of worship God is merciful to our unrighteousness. Under the law, the transgressors died without mercy. Fourth, the law continuously brought sins and iniquities to remembrance, but in the New Covenant God remembers our sins and iniquities against us no more. In New Testament worship, God is to us a God and we are to him a people.