Verses 15 and 16

to such an extent that they even carried their sick out into the streets and put them on cots and sleeping pads, so that when Peter came by at least his shadow might fall on one of them [with healing power].

And the people from the towns in the vicinity of Jerusalem were coming together, bringing the sick and those who were tormented by unclean spirits, and they were all being healed.

Jesus told His disciples before He left them that greater things will they do. The bible never recorded the shadow of Jesus healing the sick and those possessed of the devil. But, we see Peter and the apostles manifesting such power.

Lesson: In the contemporary world, the apprentice is not expected to know more than the master. But, in the christendom, God expects more from us because the grace made available to us by the atonement of Jesus, didn't only bring us into the kingdom of God by adoption, but also made us joint heirs with Christ. This does not mean we are equal wit Christ, but that we have access to the supernatural and can walk in the supernatural with/in Christ.