Many Christians do not fully understand the difference between the New Testament and the Old Testament. It is good to spend some time to study this matter.
[As we come to study the new and old testaments, we must first know the difference between these terms: a promise, an oath, a covenant, and a testament. A promise is an ordinary word spoken by God, promising you that He will do something for you. An oath is a confirmation of God’s word of promise. God confirmed His word of promise by means of His oath (Heb. 6:13, 17). When a promise is confirmed by an oath, it immediately becomes a covenant. What we have received from God is not merely an ordinary word of promise but a covenant confirmed by God’s oath and sealed with His faithfulness. When the One who made the covenant died, the covenant became a bequeathed will, that is, a testament. Today the covenant is no longer merely a covenant but a testament bequeathed by the One who enacted the covenant.]
[The new testament and the old testament are the two covenants which God made with man as the two conditions upon which man may have a relationship with Him. The new testament is a continuation of the covenant God made with Abraham. In Genesis chapter twelve, God gave a promise to Abraham and later also swore to him (Gen. 22:16). Hence, the promise became a covenant made by God with Abraham (Gal. 3:15-17). Two thousand years later, God sent His Son Jesus Christ to the world, who shed His blood on the cross and enacted the new covenant (Luke 22:20). At that point the new covenant was accomplished; moreover, it became a testament because of the Lord’s death.
The old covenant, which came four hundred and thirty years after God made the covenant with Abraham, was enacted at Mount Sinai, where God gave the law to the children of Israel. Strictly speaking, the old covenant does not cover the entire period of the Old Testament, from Genesis to Malachi. It actually began from Exodus 19 and continued until the time of John the Baptist (Matt. 11:12-13). The time of John the Baptist to the time before the death and resurrection of the Lord Jesus is a transitional period between the Old and the New Testament times. Whereas God dealt with man in the Old Testament according to the old covenant—the law, He deals with man in the New Testament according to the new covenant—grace.]
[Romans 5:20 says that “the law entered.” This word means that the law was not in God’s original intention, nor was it God’s original ordination for man. Rather, it entered later; it was added along the way.] Due to man’s fall and corruption, God added the law for the following reasons: 1) the law expresses God, in His person and attributes, to fallen man; 2) the law makes manifest man’s transgressions; 3) the law exposes man’s real condition of being unable to express God according to God’s holiness, righteousness, and glory; 4) the law guards man as a child-conductor unto Christ; and 5) the law drives man to believe and receive Christ as grace that he may live and express God according to the demand of the law (Gal. 3:19, 22-26). [Since the old covenant was something added and was not God’s original intention for man, it could not remain permanently. Rather, it became old, grew decrepit, and disappeared (Heb. 8:13).]
[Galatians 3:19 says that the law was “ordained through angels in the hand of a mediator.” The mediator here refers to Moses (John 1:17; Exo. 24:3). Hence, the law was ordained in the hand of Moses. This indicates that it was not a pleasant and sweet matter for God to give the law to man; otherwise, He would have done it Himself.]
[Man is sinful, and without shedding of blood there is no forgiveness (Heb. 9:22). Without forgiveness of sin there is no way to fulfill the requirement of God’s righteousness that by it the covenant may be enacted. Therefore, the old covenant was dedicated with the blood of bulls and goats (Heb. 9:18-20; Exo. 24:6-8).]