Watchman Nee :
The book of Acts is the best pattern for our work. In Acts we do not see someone "consecrating to be a preacher," "deciding to do the Lord's work," "becoming a missionary," or "becoming a pastor," etc. Rather, we see the Holy Spirit Himself appointing people and sending people to work. God does not recruit men to give themselves for the work; God only sends the persons whom He wants. We do not see anyone choosing to do a work himself; only God selects the laborers for His work. There is no place for the thought of man's flesh. If God wants something, even a Saul will not be able to resist. If God does not want something, even a Simon will not be able to buy it with money. As the Lord of all, God controls His own work, not allowing even a little part of man to be mixed in with it. Man does not come to work; rather, God "sends out" the laborers. Therefore, spiritual work must begin with a personal calling from the Lord Himself. One must not go forth to work because of the entreaty of preachers, the urging of relatives and friends, or the affinity of his own nature to the holy Word. Only those who are not wearing fleshly shoes can stand upon the holy ground of God's work. Much failure, waste, and confusion happen because man himself comes to work rather than being sent to work.
Book: The spiritual man -Watchman Nee