“Whereof I am made a minister, according to the dispensation of God which is given to me for you, to fulfil the word of God” (Colossians 1:25).
The Mosaic Law was not given forever; that dispensation was not meant to operate into eternity future. It was only given to Israel temporarily—namely, to prove to her that God would make her His people. The Jews could never do enough to please God: their religious efforts were utterly futile. Their nation would only exist because of God’s work. Although the Law was given to Israel, it showed all nations to be “guilty before God” (Romans 3:19). “Therefore by the deeds of the law shall no flesh be justified in his sight: for by the law is the knowledge of sin” (verse 20). Chapter 3 proceeds to explain how there came a dispensational change—Law to Grace. With that new dispensation came a new Gospel!
Another one of the major “household rules” in effect today is we are under grace, not law (Romans 6:14,15)—that goes for initial justification before God, a right standing before Him to go to heaven, as well as for daily Christian living, practical sanctification. Our performance will never measure up to God’s perfect standards. However, Jesus Christ’s performance at Calvary does please God. The Gospel of the Grace of God, Paul’s Gospel, is most clearly and succinctly defined in 1 Corinthians chapter 15: “ Moreover, brethren, I declare unto you the gospel which I preached unto you….  For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures;  And that he was buried, and that he rose again the third day according to the scriptures.”
We have a sin problem, friends, and commandments cannot help us. Thus, Jesus Christ died for our sins, shed His blood to pay for those sins, that by simple faith in Him and Him alone, we can join the Church the Body of Christ (Ephesians 2:1-22), the Holy Spirit can baptize us into Jesus Christ (1 Corinthians 12:13), all because of what Christ did, not because of our religious works… source