John 20

Jesus rose from the dead and appeared to His disciples. Thomas was not with them the first time and said he would not believe it unless he saw with his own eyes and touched Jesus' wounds. When Jesus' appeared the second time, having seen, Thomas believed.

"I'll believe it when I see it" is just human nature. No one wants to be tricked or find out after the fact that they made a mistake. Seeing something makes us feel assured that the thing we're being told is true. But it is not absolutely necessary to see a thing to believe it. Sometimes we have to rely on the eyewitness accounts of others - we can't possibly see everything that happens. Jesus said that those who believe in Him without seeing Him will be blessed. Today we have the eyewitness accounts of the New Testament writers to inform our belief. We can choose to be stubborn and continue to demand a firsthand experience of Jesus in the flesh or accept the evidence presented by those who did see Him.