Resources for Finishing Our Lord's Unfinished Work
The first account I composed, Theophilus, about all that Jesus began to do and teach, until the day when He was taken up, after He had by the Holy Spirit given orders to the apostles whom He had chosen. 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. And 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; for John baptized with water, but you shall be baptized with the Holy Spirit not many days from now." And so when they had come together, they were asking Him, saying, "Lord, is it at this time You are restoring the kingdom to Israel?" He said to them, "It is not for you to know times or epochs which the Father has fixed by His own authority; but you shall 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." And after He had said these things, He was lifted up while they were looking on, and a cloud received Him out of their sight. And as they were gazing intently into the sky while He was departing, behold, two men in white clothing stood beside them; and they also said, "Men of Galilee, why do you stand looking into the sky? This Jesus, who has been taken up from you into heaven, will come in just the same way as you have watched Him go into heaven." (1:1–11)
The work of Jesus Christ is both finished and unfinished. His great work of providing redemption is finished, and nothing may be added to it (cf. John 17:4). His work of ministry and proclamation, however, is not finished. That work He only started. Along with the other gospels, the first account composed by Luke for Theophilus (the gospel of Luke), records all that Jesus began to do and teach during His life on earth. The rest of the New Testament describes the continuation of His work by the early church. We are still finishing it until He comes.