35Heaven and earth shall pass away. In order to secure greater confidence in his statements, he illustrates their certainty by this comparison, that it is more firm and stable than the entire structure of the world. (156) But this form of expression is explained by commentators in a variety of ways. Some refer it as the passing away of heaven and earth at the last day, by which their frail constitution will be brought to an end; while others explain it to mean, that sooner shall the entire structure of the world perish than the prophecy which we have just heard shall fail to be accomplished. But as there can be no doubt that Christ expressly intended to raise the minds of his followers above the contemplation of the world, I think that he refers to the continual changes which we see in the world, and affirms, that we ought not to judge of his sayings by the changeful character of the world, which resembles the billows of the sea; for we know how easily our minds are carried away by the affairs of the world, when it is undergoing incessant change. For this reason, Christ enjoins his disciples not to allow their attention to be occupied by the world, but to look down, from what may be called the lofty watch-tower of divine providence, on all that he foretold would happen. Yet from this passage we draw a useful doctrine, that our salvation, because it is founded on the promises of Christ, does not fluctuate according to the various agitations of the world, but remains unshaken, provided only that our faith rises above heaven and earth, and ascends to Christ himself.