Therefore the Apostle urges believers to be turned away from this with such insistence. He does so not only by pointing to the harmful consequences of dispute, but also by adjuring them in the name of the Lord.
The words “remind them of these things” serve as a transition to the next main subject, the avoidance of contentiousness. Yet what came before is not unrelated to it.
“These things” means the immediately preceding word about the faithfulness of the promise of glory. It also hints at the danger of losing it, not because God is unfaithful, but because of our weakness and carelessness.
One such carelessness is then indicated: destructive contentiousness. Since there is a susceptibility to disputes, and since they are destructive, a strong means of restraining them is proposed.
Saint Chrysostom says: “What does ‘charge them before the Lord’ mean? It means calling God to witness one’s words and actions. If after this the hearers disregard the admonition, then God is their judge.
“The Apostle knew that this is common, and that the human soul is always inclined to contention and wrangling. Therefore, so that this might not happen, he does not simply say, ‘Do not wrangle over words.’ He binds them by the name of God to fulfill this.
“It is fearful to speak while bringing God as witness. If no one would dare to betray a trust after calling a man as witness, much less would he dare after calling God.”
“Of no use” does not mean merely “without any need,” but “for nothing useful,” επ’ ουδεν χρησιμον. Adjure them in the name of the Lord not to wrangle over words for this reason alone: disputes lead to nothing useful.
Having received being, and now having been counted worthy of faith and grace, we must devote every hour and minute of life to what is useful. We must do this for the glory of God, for our salvation, and for the good of our neighbors.
Dispute is vain speech. It is a disposition of empty words, yet of such words as can do harm. In this last point lies a second motive for abstaining from disputes.
“For from this comes not only no benefit, but great harm: the overthrow of the hearers,” says Saint Chrysostom.
The disputing opponent of truth spares no one. Casting words about at random, he can cast many thoughts and images into the minds of hearers. These then begin to shake faith.
They do this not by their own strength, but because of the weakness of the hearers. Such hearers do not yet know how to see the hidden falsehood beneath fine phrases.
Ambrosiaster writes: “Dispute can produce doubts in those not yet fully established. In dispute, many things are customarily set against the truth. These can strike the souls of beginners with the sharpened sword of malice and slander.”
Thus by disputes “the faith of the hearers is overturned, like some pillar by the siege engines of word battles,” says blessed Theophylact.
As for us, “we must only believe, and not turn discussion of this into an occasion for blasphemy. Nor should we harm the hearers by our disputing,” says blessed Theodoret.