Jesus explains in the New Testament that miracles are performed by faith in God. "If you have faith as small as a mustard seed, you can say to this mountain, 'move from here to there' and it will move." (Gospel of Matthew 17:20). After Jesus returned to heaven, the Book of Acts records the disciples of Jesus praying to God to grant that miracles be done in his name for the purpose of convincing onlookers that he is alive. (Acts 4:29–31).