While preparing for a sermon recently I found help from John Calvin in his commentary on Acts 11:21. Below is not the entire quote, but a sizable portion. It’s very encouraging to all Christians, but especially the gospel minister, in that it reminds us that it’s the Lord who must bless. He says

This place did also teach us, that what pains soever the ministers of God take in teaching, it shall be all vain and void, unless God bless their labours from heaven. For we may plant and water, as Paul teacheth, but the increase cometh from God alone…in whose hand the hearts of men are…Therefore, let the minister attempt nothing trusting to his own wit and industry, but let him commit his labour to the Lord, upon whose grace the whole success dependeth…[1]

[1] John Calvin, Calvin’s Commentaries Volume XVIII: Commentary upon the Acts of the Apostles (Grand Rapids: Baker, 1998), 467-468.