There is another approach possible. Those who have embraced a strong doctrine of the grace of God may struggle a little in coming to terms with a commission which lays upon them the responsibility of making disciples. It would be difficult to quibble with such people when they insist that it is God and not man who makes disciples. We can however respond in two ways. In the first place we can point out that we are "workers together with God" (1 Cor 3.9; 2 Cor 6.1). There is a strong element of mystery in so many aspects of our labouring for God, e.g. in the ministry of preaching. So, at the very least, we can say that God uses his people in the making of disciples. In the second place we can point out that for the Reformers our contribution to the making of disciples was in fact through the preaching of the Gospel. John Calvin states, "The Lord, when he sent out the apostles, gave them the command to preach the Gospel and to baptise those who believe unto forgiveness of sins (Matt 28.19)." Institutes of the Christian Religion IV 6, Westminster Press 1977, Vol 2, p1058. See also JM Boice, Foundations of the Christian Faith , IVP 1986, p 653: "Jesus not only commands us to evangelise, he also tells us how to do it. First, we are to make disciples of all nations. We are to preach the Gospel to them so that through the power of the Scriptures and the Holy Spirit they are converted from sin to Christ and there after follow him as their Lord…"
On this basis it is simply assumed in the Great Commission that disciples are made through the proclamation of the Gospel which is received through faith. As Beasley-Murray rightly observes: "the kerygma precedes the didache, the offer of grace before the ethics of discipleship, and it is when the gospel of grace is received that the ethics of gratitude may be learned and applied. "Baptism in the New Testament, Paternoster 1962, pp 89f. So, those who become disciples, through the proclamation of the gospel, are then baptised, and after they are baptised they devote themselves to the teaching of the apostles. That is precisely the pattern we find on the very first occasion that the Great Commission was put into operation, as recorded in the Book of Acts: the preaching of the Gospel, the response of faith, baptism, devotion to the apostles' teaching (2.14-47). Unless we adopt the position that the apostles misunderstood Jesus and got it wrong we must conclude that the correct exegesis of Matthew 28.19 is to be found in Acts 2. The apostles were certainly in a better position to rightly understand Jesus' meaning than we are two thousand years later!
What was true on the Day of Pentecost was true throughout the New Testament era. How did the apostles make disciples of the Gentiles (i.e. the nations)? They did so by preaching the Gospel. The Lord told Ananias concerning Saul, "This man is my chosen instrument to carry my name before the Gentiles…and before the people of Israel"(Acts9.15).It was this same man, Saul become Paul, who subsequently cried out, "Woe tome if I do not preach the Gospel" and who also informs us that he hardly baptised anyone (1 Cor 1.14). That is not to detract from the importance of baptism but to emphasise that in Paul's view it was not the essential thing in making disciples.