29And when they had fulfilled all that was written of him, they took him down from the tree, and laid him in a sepulchre. 30But God raised him from the dead: 31And he was seen many days of them which came up with him from Galilee to Jerusalem, who are his witnesses unto the people. 32And we declare unto you glad tidings, how that the promise which was made unto the fathers, 33God hath fulfilled the same unto us their children, in that he hath raised up Jesus again; as it is also written in the second psalm, Thou art my Son, this day have I begotten thee. 34And as concerning that he raised him up from the dead, now no more to return to corruption, he said on this wise, I will give you the sure mercies of David. 35Wherefore he saith also in another psalm, Thou shalt not suffer thine Holy One to see corruption. 36For David, after he had served his own generation by the will of God, fell on sleep, and was laid unto his fathers, and saw corruption: 37But he, whom God raised again, saw no corruption. 38Be it known unto you therefore, men and brethren, that through this man is preached unto you the forgiveness of sins: 39And by him all that believe are justified from all things, from which ye could not be justified by the law of Moses.
Comment: This is one of the scriptures showing there were many eyewitnesses to Jesus' resurrection. We know this because there were many disciples accompanying Jesus on the trip from Galilee to Jerusalem where he was crucified. According to Luke 9:51 and 10:1, there were at least 72 disciples that accompanied Jesus on this trip. Also, in Acts 1:15 we see there were about 120 gathered together. Most of the 120 people were probably the same ones who came from Galilee with Jesus. In the passage at hand Luke records Paul and Barnabas saying the resurrected Jesus had appeared to these people over many days. We then see Paul agreeing with these witnesses even though their experience had occurred earlier than his. Apparently his independent experience with the resurrected Jesus had much in common with earlier witnesses one of them being Barnabas. Otherwise how could Paul and Barnabas agree on what to say? After establishing the credibility of the resurrection through eyewitness accounts, Paul goes on to argue from scripture the Messiah had to be raised from the dead. Also prophecy indicated the raised Messiah would not be in the grave long enough for the body to decay. Since Jesus was raised from the dead before his body decayed, it had to be he that was the Messiah. Further Paul shows the psalm he quotes has to be a prophecy since the body of David, the psalm writer, had not been resurrected and instead had decayed. So we can see that Jesus not only had eyewitnesses to his resurrection, but the prophetic scriptures indicated this was to occur.