First, there were the gospel events, primarily the death and resurrection of Jesus. Sometimes the apostles began with a reference to the life and ministry of the man Jesus, and usually they went on to his enthronement as Lord and his return as Judge. But their message focused on his death and resurrection. Nor did they proclaim these (as some say) as non-theological history, just “you killed him, but God raised him.” Already they had a doctrine of both. His death was “according to the definite plan and foreknowledge of God” (Acts 2:23), and the Cross on which it took place they deliberately called a “tree” to indicate the divine curse under which he died (Acts 5:30, 10:39, 13:29; Deut. 21:22, 23; Gal. 3:10, 13; 1 Pet. 2:24), while the resurrection was a divine vindication, snatching him from the place of a curse to the place of honor and authority at God’s right hand (e.g., Acts 2:32, 33).
Second, there were the gospel witnesses. That is, the apostles proclaimed the death and resurrection of Jesus both “according to the Scriptures” (Acts 2:25ff, 3:18, 24; cf. 1 Cor. 15:3, 4) and according to the evidence of their own eyes. “We are witnesses of these things, “they kept saying (e.g., Acts 2:32, 5:32). So we today have no liberty to preach Christ crucified and risen according to our own fancy or even according to our own experience. The only Christ there is to preach is the biblical Christ, the objective historical Jesus attested by the joint witness of the prophets of the Old Testament and the apostles of the New (cf. Acts 10:39-43). Our witness is always secondary to theirs.
Third, there were the gospel promises. The apostles did not proclaim the death and resurrection of Jesus merely as events, even when enriched by doctrinal significance and biblical witness. For the good news concerns not just the historic but the contemporary Christ, not just what he once did but what he now offers on the basis of what he did. What is this? In Peter’s Pentecost address, the very first Christian sermon ever preached, he was able to promise them with complete assurance that they could receive both “the forgiveness of sins” and “the gift of the Holy Spirit” (Acts 2:38). Salvation is more than this, but it is certainly not less. It includes the remission of past guilt and the gift of an entirely new life through the regenerating and indwelling Holy Spirit.
Fourth, there were the gospel demands, namely repentance and faith….