They might be with Him. 

“He appointed Twelve, whom he also named Apostles, that they might be with him, and he might send them forth to preach and to have authority to drive out demons.” (MK 3: 14-15)

This is the basis of every vocation: “be with.” Before any action, before any mission, there is always communion of persons. “To be” is always more important than “to do.” And every good “to do” comes from good “to be.” Agere sequitur esse–action follows being. This is about marriage, and this is about the priesthood; this is about parenting, and this is about consecrated life. Action requires a person; amazing actions require an amazing person. 

“God was reconciling the world to himself in Christ, and entrusting to us the message of reconciliation.” (Gospel Acclamation)