We have 11 early sources that the disciples willingly died for their testimony of having seen Jesus alive from the dead (The Case for the Resurrection of Jesus, by Gary R. Habermas).

No less than 9 ancient sources from an eyewitness, very early oral traditions dating within 20 years of Jesus' crucifixion, and several written sources testify that Jesus' disciples were claiming that he had risen from the dead and appeared to them.

"It may be taken as historically certain that Peter and the disciples had experiences after Jesus' death in which He appeared to them as the risen Christ." (Atheist New Testament Scholar Gerd Lüdemann, 1995)

The original disciples were willing to suffer and die for their belief that Jesus rose and attests to the sincerity of their faith, which strongly rules out lies on their part. (Sources: Luke, Clement of Rome, Polycarp, Ignatius, Dionysius of Corinth, Tertullian, Origen.)

"The credibility of the apostle Paul's testimony that he also had an experience that he believed was an appearance of the risen Jesus is recognized by virtually all scholars. Likewise well recognized is that James, the brother of Jesus, was an unbeliever before he thought that he, too, met the risen Jesus. Seldom are any of these occurrences challenged by respected critical scholars, no matter how skeptical." (Gary Habermas, Liberty University, 2003)

The church persecutor Paul experienced an immediate change from a persecutor of the Church to one of its most aggressive advocates. He said the change was because the risen Jesus had appeared to him, and he willingly suffered and died for that belief. (Sources: Paul, Luke, Clement of Rome, Polycarp, Tertullian, Dionysius of Corinth, Origen)

Almost all skeptical scholars testify Paul wrote 1 Cor. 15, Gal. 1 & 2 in which he said the creed he received of the resurrection of Jesus, he received from Peter, James and John whom he met personally.

The skeptic James, the brother of Jesus:

A. Prior to Jesus' resurrection, the brother of Jesus named James was a skeptic (Sources: Mark, John).

B. An appearance of the risen Jesus to James is reported within 5 years of Jesus' crucifixion (Source: 1 Corinthians 15:7).

C. James became a leader of the Church in Jerusalem (Sources: Paul, Luke).

D. James willingly died for his belief that Jesus was the Messiah (Sources: Josephus, Hegesippus, Clement of Alexandria).