Daniel Block, reflecting on Ezekiel’s call to ministry in Ezek 3 notes an important theological implication concerning the “call” to ministry. His statement is not meant to be an exhaustive treatment of the subject yet it’s worth considering.
First, whoever would serve as a messenger of God must recognize that the calling comes from God alone. Neither the needs of the field, nor oratorical gifts, nor any other external qualifications authorize one to enter divine service. Moreover, the God who appoints his servants also defines the task, chooses the field of serivce, provides the message, and assumes repsonsibility for the outcome. The less evident the fruit for one’s ministry, the more critical is a clear sense of calling.
from Daniel I. Block, The Book of Ezekiel Chapters 1-24, NICOT, 130.