Picture the scene in John 20:19-31. All the disciples except Thomas are in a room behind locked doors at night. It was common for early Christians to meet at night. In times of persecution they were forbidden to meet during the day, so they had to meet at night. The disciples are scared. They saw their leader brutally killed, and they are afraid that they will also be killed. In more ways than one, the room and the situation are dark.
Suddenly, Jesus appears. He walks through the locked door. The first words Jesus says to the assembled disciples are, “Peace be with you.” They are terrified, first for fear of the Jews and because they thought they were seeing a ghost. But when Jesus shows them His wounds, they know this is their Lord. Jesus promised the Holy Spirit would come. Just as God created humanity with His breath in Genesis 2:7, He gave the Holy Spirit to His disciples by breathing on them. God is recreating humanity in Christ. The darkness of the room is dispelled by the light of Christ.
Jesus gave the disciples and us a mission, but we and they can’t begin this mission of healing and peace without the power and energy of Jesus’ risen life. Jesus breathed on these men. As God breathed His life into that first man and he became a living soul, Jesus shared the intimacy of His own life with His disciples that they may be a new humanity, recreated and empowered for their mission.