John Calvin Commentary Acts 21:17

"And when we were come to Jerusalem, the brethren received us gladly." — Acts 21:17 (ASV)

They received us gladly. Luke recounts this to set forth the fairness of the brothers, who did not believe rumors and false reports. Although many envious and wicked men daily, one after another, tried to bring Paul into contempt, James and his colleagues were so convinced of Paul's integrity that they were not alienated from him. Therefore, they now received him graciously and in a brotherly way as a servant of Christ, declaring that he was welcome.

We must diligently observe this restraint, so that we are not too quick to believe wicked reports. This is especially important when those who have given some testimony of their honesty, and whom we have known to serve God faithfully, are accused of crimes unknown to us or that are uncertain.

Because Satan knows that nothing is more effective in destroying the kingdom of Christ than discord and disagreement among the faithful, he does not cease to spread false reports that can cause suspicion among people. Therefore, we must close our ears to these false reports, so that we believe nothing about the faithful ministers of the Word except what we know to be true.