In our Gospel today, Jesus calls the 12 apostles to be with him, to preach, and to cast out demons. Only demons are their enemies, not people who disagree with them or even oppose them. For these people, the apostles should give witness to their joy and friendship with Jesus to perhaps win them over. This is good advice for us today as well.
Based on Mark 3:13-19:
Jesus went up the mountain and called to him those whom he wanted, and they came to him. And he appointed twelve, whom he also named apostles, to be with him, and to be sent out to proclaim the message, and to have authority to cast out demons. So he appointed the twelve: Simon (to whom he gave the name Peter); James son of Zebedee and John the brother of James (to whom he gave the name Boanerges, that is, Sons of Thunder); and Andrew, and Philip, and Bartholomew, and Matthew, and Thomas, and James son of Alphaeus, and Thaddaeus, and Simon the Cananaean, and Judas Iscariot, who betrayed him.
(New Revised Standard Version Bible: Anglicized Edition, copyright © 1989, 1995 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved worldwide. http://nrsvbibles.org)