Albert Barnes on James 3:14

But if ye have bitter envying and strife in your hearts. If that is your characteristic. There is reference here to a fierce and unholy zeal against each other; a spirit of ambition and contention.

Glory not. Do not boast, in such a case, of your qualifications to be public teachers. Nothing would render you more unfit for such an office than such a spirit.

And lie not against the truth. You would lie against what is true by setting up a claim to the requisite qualifications for such an office, if this is your spirit. Men should seek no office or station which they could not properly seek if the whole truth about them were known.