Jesus spoke openly about what would happen to him: crucifixion and then resurrection from the dead. "The Son of Man must suffer many things and be rejected by the elders and the chief priests and the scribes and be killed, and after three days rise again" (Mark 8:31; see also Matthew 17:22; Luke 9:22). Those who consider the resurrection of Christ unbelievable will probably say that Jesus was deluded or (more likely) that the early church put these statements in his mouth to make him teach the falsehood that they themselves conceived. But those who read the Gospels and come to the considered conviction that the one who speaks so compellingly through these witnesses is not the figment of foolish imagination will be unsatisfied with this effort to explain away Jesus' own testimony to his resurrection from the dead.
This is especially true in view of the fact that the words which predict the resurrection are not only the simple straightforward words quoted above, but also the very oblique and indirect words which are far less likely to be the simple invention of deluded disciples. For example, two separate witnesses testify in two very different ways to Jesus' statement during his lifetime that if his enemies destroyed the temple (of his body), he would build it again in three days (John 2:19; Mark 14:58; cf. Matthew 26:61). He also spoke allusively of the "sign of Jonah" - three days in the heart of the earth (Matthew 12:39; Matthew 16:4). And he hinted at it again in Matthew 21:42 - "The very stone which the builders rejected has become the head of the corner." On top of his own witness to the coming resurrection, his accusers said that this was part of Jesus' claim: "Sir, we remember how that impostor said, while he was still alive, ‘After three days I will rise'" (Matthew 27:63).
Our first evidence of the resurrection, therefore, is that Jesus himself spoke of it. The breadth and nature of the sayings make it unlikely that a deluded church made these up. And the character of Jesus himself, revealed in these witnesses, has not been judged by most people to be a lunatic or a deceiver.
Taken from "Eight Reasons Why I Believe That Jesus Rose from the Dead" by John Piper. © Desiring God. Website: www.desiringGod.org (used by permission).