Having this confidence--This “I know” of the apostle has something like its parallel in that of Luther, when his friend and true yoke fellow, Melancthon, lay at the point of death.
The reformer, it is said, after earnest prayer approached the sick bed, and uttered these prophetic words, “Cheer up, Philip; you are not going to die.” Luther was in no sense prophesying, but he had been praying; and in answer to his prayer the conviction was irresistibly borne in upon his mind and heart, that his colleague, for whom so much work was waiting, would yet live to do it. What, then, of personal conviction Luther asserted about another, Paul here asserts about himself. We thus see that blended humility and trustfulness, more especially in strongly emotional natures, can dare sometimes to use the bold language of assured conviction even in regard to issues which are to us uncertain, for they are with God alone. But it is to be noticed that this language never can be used when merely personal or private ends are in view. When Paul said “I know” in this case, he was indeed alluding to his own future, but he was contemplating it in relation not to his own individual interests, but solely to his friends’ “progress and joy in the faith,”--their advancement in the inner life through strengthening faith, and their joy, as overflowing out of that faith, in their outward life of Christian service. All this would be theirs by his presence restored to them for a time, more than by any letter, however tender, he could write to them. (J. Hutchison, D. D.)