When John the Baptist appeared as Christβs forerunner, Godβs chosen people had lived under the law of Moses for fifteen hundred years but had not kept it. Hence Johnβs call to repentance and baptism for the remission of sins (Mark 1:4).
John was in earnest, too, for when the thoughtless multitude came to him to be baptized, he sent them back, saying: βBring forth fruits worthy of repentanceβ (Luke 3:7,8).
Their lives were to be changed and they were to show it. When the people asked: βWhat shall we do, then?β he told them to live for others rather than for self (Luke 3:10,11). When the tax collectors asked: βWhat shall we do?β he demanded that they stop cheating the tax payers and live honestly (Luke 3:12,13). When the soldiers asked: βWhat shall we do?β he told them to forbear violence, false accusation and bribery (Luke 3:14).
Clearly, righteousness was demanded under Johnβs message. His hearers were to repent, be baptized, and bring forth the fruits of true repentance. When our Lord appeared, He proclaimed the same message as John (Matt. 3:1,2; 4:17). A lawyer asked: βWhat shall I do to inherit eternal life?β and He replied: βWhat is written in the law?β When the lawyer recited the basic commands of the Law, our Lord answered: βThis do and thou shalt liveβ (Luke 10:25-28). God was still demanding righteousness. They were all under the Law (Gal. 4:4,5; Matt. 23:1,2; etc.).
Some suppose this was all changed after Calvary by the so-called βgreat commission.β This is not so. When, at Pentecost, Peterβs hearers were convicted of their sins and asked βWhat shall we do?β Peter commanded them to βrepent and be baptizedβ¦ for the remission of sinsβ just as John had done (Mark 1:4; cf. Acts 2:38). He did not tell them that Christ had died for their sins.
Paul was the first to say: βBut now the righteousness of God without the law is manifestedβ¦ [We] declare His righteousness for the remission of sinsβ (Rom. 3:21-26). When the Gentile jailor fell on his knees and asked: βWhat must I do to be saved?β Paul replied: βBelieve on the Lord Jesus Christ and thou shalt be savedβ (Acts 16:30,31). This is Godβs message for sinners today, for βwe have redemption through [Christβs] blood, the forgiveness of sins according to the riches of His graceβ (Eph. 1:7). source