John 20:19, 21-29

So when it was evening on that same day, the first day of the week, though the disciples were [meeting] behind barred doors for fear of the Jews, Jesus came and stood among them, and said, “Peace to you.”

Then Jesus said to them again, “Peace to you; as the Father has sent Me, I also send you [as My representatives].” And when He said this, He breathed on them and said to them, “Receive the Holy Spirit. [Acts 1:8; 2:1-3] If you forgive the sins of anyone they are forgiven [because of their faith]; if you retain the sins of anyone, they are retained [and remain unforgiven because of their unbelief].” But Thomas, one of the twelve [disciples], who was called Didymus (the twin), was not with them when Jesus came. So the other disciples kept telling him, “We have seen the Lord!” But he said to them, “Unless I see in His hands the marks of the nails, and put my finger into the nail prints, and put my hand into His side, I will never believe.” Eight days later His disciples were again inside the house, and Thomas was with them. Jesus came, though the doors had been barred, and stood among them and said, “Peace to you.” Then He said to Thomas, “Reach here with your finger, and see My hands; and put out your hand and place it in My side. Do not be unbelieving, but [stop doubting and] believe.” [Luke 24:39] Thomas answered Him, “My Lord and my God!” Jesus said to him, “Because you have seen Me, do you now believe? Blessed [happy, spiritually secure, and favored by God] are they who did not see [Me] and yet believed [in Me].”