“Not many of you should become teachers, my brothers, for you know that we who teach will be judged with greater strictness.” James 3:1
"James here refers not to the men who perform public duties in the Church, but to those who usurp to themselves the right to pass censure on others. These are the critics, who like to be regarded as the shepherds of morality. They turn the fault-finding look of superiority upon others. Alas, it is an innate condition of the human make-up, to make one’s reputation by scoring off other folk.
Note that James is not discouraging those fraternal admonitions, which the Spirit so much and so often presses upon us, but is condemning an excessive passion, which springs from self-seeking and pride, whereby one man inveighs against his fellow, speaks against him, sneers at him, snaps and rummages about to find something to use to his harm--be it but hearsay.
It is usually the case that persistent critics of this sort make wild claims in hunting down the faults of others. Such is the immoderate and arrogant behavior from which James bids us to turn back.
Such critics, after all, give themselves a hard standard when they force everyone’s words and deeds to the utmost rigor; they do not find pardon, who cannot bear to pardon another.” --John Calvin