The whole Church is apostolic, in that she remains, through the successors of St. Peter and the other apostles, in communion of faith and life with her origin: and in that she is "sent out" into the whole world. All members of the Church share in this mission, though in various ways. "The Christian vocation is, of its nature, a vocation to the apostolate as well." Indeed, we call an apostolate "every activity of the Mystical Body" that aims "to spread the Kingdom of Christ over all the earth."