Monergism

Most churches make the mistake of selecting as leaders the confident, the competent, and the successful. But what you most need in a leader is someone who has been broken by the knowledge of his or her sin, and even greater knowledge of Jesus' costly grace. The number one leaders in every church ought to be the people who repent the most fully without excuses, because you don't need any now; the most easily without bitterness; the most publicly and the most joyfully. They know their standing isn't based on their performance.
Timothy J. Keller

Apart from union with Christ, ministry is cast back upon us to achieve. This is a recipe for failure, for we all fall short of the glory of God. The understanding and practice of pastoral work in this case is a burden too heavy to bear and follows a path that denies the gospel. We do not heal the sick, comfort the bereaved, accompany the lonely, forgive sins, raise up hope of eternal life, or bring people to God on the strength of our piety and pastoral skill. To think that these tasks are ours to perform is not only hubris, but also a recipe for exhaustion and depression in ministry.
Andrew Purves Reconstructing Pastoral Theology (pg. 45)