Acts 1:1-3

NLT: ¹Dear Theophilus: In my first book I told you about everything Jesus began to do and teach ² until the day he ascended to heaven after giving his chosen apostles further instructions from the Holy Spirit. ³During the forty days after his crucifixion, he appeared to the apostles from time to time and proved to them in many ways that he was actually alive. On these occasions he talked to them about the Kingdom of God.

NIV: ¹In my former book, Theophilus, I wrote about all that Jesus began to do and to teach ²until the day he was taken up to heaven, after giving instructions through the Holy Spirit to the apostles he had chosen. ³After his suffering, he showed himself to these men and gave many convincing proofs that he was alive. He appeared to them over a period of forty days and spoke about the kingdom of God.

NASB: ¹The first account I composed, Theophilus, about all that Jesus began to do and teach, ²until 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. ³To 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.

KJV: ¹The former treatise have I made, O Theophilus, of all that Jesus began both to do and teach, ²Until the day in which he was taken up, after that he through the Holy Ghost had given commandments unto the apostles whom he had chosen: ³To whom also he showed himself alive after his passion by many infallible proofs, being seen of them forty days, and speaking of the things pertaining to the kingdom of God:

Comment: Luke ties this book, Acts, to his gospel, Luke. The comments concerning Luke 1:1-4, wherein Luke claims to have thoroughly investigated everything including eyewitness accounts of Jesus resurrection, apply here as well. In the passage at hand Luke indicates a specific period of 40 days during which the resurrected Jesus visited his discipless. Having a specific period of time designated in the account gives it credibility as specifics are a significant means for supporting or denying assertions. Further, Luke goes on to state the resurrected Jesus spent a good portion of that time dispelling any doubts that he had been raised from the dead. Surely Jesus' continued appearances occurring to dispell doubt would not have been needed had not the resurrection been something that stretched the willingness to believe in the disciples themselves. The need for assurance among the original disciples, in itself, provides credibility to the account. False accounts do not typically contain doubts about their veracity since one of the main ideas is to divert attention from scrutiny. Expressing doubt in the narrative highlights the need the disciples themselves had for believing Jesus was raised from the dead. And, more importantly, that need was satisfied.