Ministry is often examined in terms of who the minister is, not what the minister does. But the vocation to ministry must be understood as a call to identity as well as to practice, one that is rooted in Jesus' life and ministry as well as the Spirit's charisms. In Introducing the Practice of Ministry Kathleen A. Cahalan defines ministerial leadership as carried out through the practices of teaching, preaching, pastoral care, worship, social ministry, and administration for the sake of nurturing the life of discipleship in the community of believers. In her examination of charisms for each of the practices of ministry, Cahalan presents readers with a Trinitarian foundation, noting that "the practices of discipleship and ministry have their origin in the very practices of God."