12 By Silvanus He exhorts them at the conclusion of the Epistle to constancy in the faith: yea, he declares that his design in writing, was to retain them in obedience to the doctrine which they had embraced. But he first commends the brevity of his Epistle, lest the reading of it should be tedious to them; and, secondly, he adds a short commendation of his messenger, that the living voice might be added to what was written; for this was the design of the testimony he bears to his fidelity. But the exception, as I suppose, or think, was added, either as token of modesty or to let them surely know, that he spoke according to the conviction of his own mind; and it was unreasonable for them not to assent to the judgment of so great an apostle.
Exhorting and testifying How difficult it is to continue in the faith! evidences of this are the daily defections of many: nor, indeed, is such a thing to be wondered at, when we consider how great is the levity and inconsistency of men, and how great is their inclination to vanity. But as no doctrine can strike firm and perpetual roots in men’s hearts, if it be accompanied with any doubt, he testifies that God’s truth, in which they had been taught, was certain. And, doubtless, except its certainty appears to our minds, we must at all times necessarily vacillate, and be ready to turn at every wind of new doctrine. By the grace of God, he means faith with all its effects and fruits.