How would people in later years believe in Christ? “Through their word” (John 17:20). That is, by the report of those first disciples, especially the apostles. Jesus gave them the work of being witnesses, to tell others the truth about Him (Luke 24:48; Acts 10:39-41). As He sent them into the world, Jesus said,
“… You will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth” (Acts 1:8).
However, at the time when this was said, one of the twelve was missing. Judas had turned against Jesus, and killed himself. Another had to be chosen to take his place. The importance of finding a real witness was shown by Simon Peter’s words,
So one of the men who have accompanied [been with] us during all the time that the Lord Jesus went in and out among us, beginning from the baptism of John until the day when He was taken up from us—one of these men must become with us a witness to his resurrection (Acts 1:21-22).
Resurrection is coming alive again after dying. Yes, Jesus wanted the apostles to be with Him so that they could be true witnesses. They were in the best place to see and know the truth about Jesus. They were the kind of witnesses that any good court of law welcomes. They were ordinary people. They had normal questions and doubts when they first heard about Jesus. But what they saw for themselves removed doubts and fears. There were many witnesses from different backgrounds and interests. Like all witnesses, they spoke about their experiences in different ways. When carefully compared, these testimonies agree. There is nothing confusing or missing. The apostles, and those closest to them, gave a full and clear report. They remained united, and true to this report, for all of their lives. The collection of their reports and letters is called the New Testament.