In the sermon 'The Holy Spirit's Call' by David Green, the speaker emphasizes that the individuals involved in the preaching work were not self-appointed or freelance preachers, but rather were specifically called by God. The role of the church is also highlighted; while the church did not initially call these individuals, it played a crucial role in sending them forth. This underscores the collaboration between the Holy Spirit, the individuals called, and the church. The sermon points out the importance of the Holy Spirit's involvement in guiding both the men and the church to fulfill God's work.

They didn't call themselves. They didn't go out freelance preaching, but they were called of God into the work that the Lord had called them to. Also we noticed that the church did not call them. Now the church sent them, that's important, but the Holy Spirit worked not only with the men but also with the church.