John Calvin Commentary Acts 11:24

"for he was a good man, and full of the Holy Spirit and of faith: and much people was added unto the Lord." — Acts 11:24 (ASV)

For he was a good man. Barnabas is commended with the commendation of the Holy Ghost; yet we must know that this was recorded not so much for his sake as for ours. For all those are condemned for ungodliness and malice who envy the labors of others, and are grieved when they see them have good success.

We must also note the epithet used in his description: a good man, full of the Holy Ghost, full of faith. For after he had said that he was an upright and good man, he showed from what fountain this goodness flowed: that, abandoning the affections of the flesh, he embraced godliness with all his heart, having the Spirit as his guide. But why does he separate faith from the Spirit, whose gift it is? I answer that it is not named separately, as if it were a different thing, but is rather set forth as a principal sign, by which it might appear that Barnabas was full of the Holy Ghost.

There was a great multitude added. Though the number of the godly was already great, Luke says that it was increased by Barnabas’s coming. Thus the building of the Church goes forward when one helps another with mutual consent, and one gently allows what another has begun.