The first account I composed, Theophilus, about all that Jesus began to do and teach, 2 until the day when He was taken up to heaven, after He had by the Holy Spirit given orders to the apostles whom He had chosen. 3 To these He also presented Himself alive after His suffering, by many convincing proofs, appearing to them over a period of forty days and speaking of the things concerning the kingdom of God. 4 Gathering them together, He commanded them not to leave Jerusalem, but to wait for what the Father had promised, “Which,” He said, “you heard of from Me; 5 for John baptized with water, but you will be baptized with the Holy Spirit not many days from now.” 6 So when they had come together, they were asking Him, saying, “Lord, is it at this time You are restoring the kingdom to Israel?” 7 He said to them, “It is not for you to know times or epochs which the Father has fixed by His own authority; 8 but you will receive power when the Holy Spirit has come upon you; and you shall be My witnesses both in Jerusalem, and in all Judea and Samaria, and even to the remotest part of the earth.” Acts 1:1–8
The Prologue - The marvelous history of Acts is told by Luke (the Physician, Col. 4:14; 2Tim. 4:11) to Theophilus (“God-lover”). This is what Jesus began to do until His ascension. Now He is continuing to work and reveal His will through His “martyrs.” The structure of Jesus’ work is: a) Jesus direct ministry; b) His Kingdom ministry through the Church. The basis for this mission is the suffering and Resurrection of Jesus. Over forty days after death, Jesus presented Himself not only the twelve, but more than 500 brethren (1Cor. 15).
The Promise - The Holy Spirit has come upon the Church, the renewed Israel, to empower us as “witnesses” (martus) to gospelize the world: first Jerusalem, then Judea, Samaria, even to the last (eschatos) part of the earth. The empowering of the messengers came by the Baptism of the Spirit at Pentecost. Calvin said this is "the beginning of the reign of Christ, and, as it were, the renewal of the world is being depicted here . . . an account of the reign of Christ beginning with His triumphant resurrection and exaltation, and continuing until His gospel has reached Rome itself, as Christ our king, puts all enemies under his feet.” The apostles did not understand all of this (e.g., v 6 and the Gentiles inclusion, ch. 10, 11, 15). The did not understand the “continuing” work of the Kingdom at that time. They ask, “Lord, will You at this time restore the kingdom to Israel?” The answer is two-fold: “It is not for you to know times or seasons” and “You shall receive power” to be “witnesses.” We now see the resurrection, the ascension, Pentecost, and the inclusion of the Gentiles (ch. 11), and further revelation by the apostles. Thus, now we understand Christ’s reign until all His enemies are subdued (1Cor. 15:22ff), the last enemy is death and the consummation of the final Resurrection.
"For as in Adam all die, so also in Christ all will be made alive. 23 But each in his own order: Christ the first fruits, after that those who are Christ’s at His coming, 24 then comes the end, when He hands over the kingdom to the God and Father, when He has abolished all rule and all authority and power. 25 For He must reign until He has put all His enemies under His feet. 26 The last enemy that will be abolished is death." 1 Corinthians 15:21–26