Romans 5:3

3.Not only so, etc. That no one might scoffingly object and say, that Christians, with all their glorying, are yet strangely harassed and distressed in this life, which condition is far from being a happy one, — he meets this objection, and declares, not only that the godly are prevented by these calamities from being blessed, but also that their glorying is thereby promoted. To prove this he takes his argument from the effects, and adopts a remarkable gradation, and at last concludes, that all the sorrows we endure contribute to our salvation and final good.

By saying that the saints glory in tribulations, he is not to be understood, as though they dreaded not, nor avoided adversities, or were not distressed with their bitterness when they happened, (for there is no patience when there is no feeling of bitterness;) but as in their grief and sorrow they are not without great consolation, because they regard that whatever they bear is dispensed to them for good by the hand of a most indulgent Father, they are justly said to glory: for whenever salvation is promoted, there is not wanting a reason for glorying.

We are then taught here what is the design of our tribulations, if indeed we would prove ourselves to be the children of God. They ought to habituate us to patience; and if they do not answer this end, the work of the Lord is rendered void and of none effect through our corruption: for how does he prove that adversities do not hinder the glorying of the faithful, except that by their patience in enduring them, they feel the help of God, which nourishes and confirms their hope? They then who do not learn patience, do not, it is certain, make good progress. Nor is it any objection, that there are recorded in Scripture some complaints full of despondency, which the saints had made: for the Lord sometimes so depresses and straitens for a time his people, that they can hardly breathe, and can hardly remember any source of consolation; but in a moment he brings to life those whom he had nearly sunk in the darkness of death. So that what Paul says is always accomplished in them —

“We are in every way oppressed, but not made anxious; we are in danger, but we are not in despair; we suffer persecution, but we are not forsaken; we are cast down but we are not destroyed.”
(2 Corinthians 4:8.)

Tribulation produces (efficiat) patience, etc. This is not the natural effect of tribulation; for we see that a great portion of mankind are thereby instigated to murmur against God, and even to curse his name. But when that inward meekness, which is infused by the Spirit of God, and the consolation, which is conveyed by the same Spirit, succeed in the place of our stubbornness, then tribulations become the means of generating patience; yea, those tribulations, which in the obstinate can produce nothing but indignation and clamorous discontent.