John Calvin Commentary Acts 9:3

"And as he journeyed, it came to pass that he drew nigh unto Damascus: and suddenly there shone round about him a light out of heaven:" — Acts 9:3 (ASV)

As he was on the way. In seeking letters from the high priest, he willingly rushed headlong against Christ; and now he is forced to obey whether he wants to or not. This is surely the most excellent mercy of God, in that this man is reclaimed for salvation contrary to his own intentions, whom such great fervor carried headlong into destruction.

The Lord allowed him to receive letters and to come near the city. This demonstrates how well God knows the precise moments to do everything at the proper time.

Indeed, He could have prevented Paul sooner, if He had chosen, in order to deliver the godly from fear and negligence.

But God displays His benefits more clearly in this: He ties the jaws of the greedy wolf just as he was ready to enter the sheepfold. Also, we know that human stubbornness increases more and more with persistence. Therefore, Paul’s conversion was all the more difficult, since he had already become more obstinate by persisting in his fury.

Shined about him. It was no easy task to humble such great pride, to break such a haughty spirit, to calm such a blind fervor of wicked zeal, and, finally, to restrain a completely unrestrained beast. Therefore, Christ necessarily had to show some sign of His majesty, so that Paul might perceive that he was dealing with God Himself and not with any mortal man.

Yet, consideration was also given to humbling him—because he was unworthy of Christ—in order to accustom him promptly to obedience by placing upon his neck the gentle and sweet yoke of His Spirit.

And he was scarcely capable of such great gentleness until his cruelty was broken. Human understanding cannot comprehend the divine glory of Christ as it truly is.

But just as God often assumed forms in which He revealed Himself, so Christ now declared and manifested His divinity to Paul. He showed some sign of His presence so that He might thereby terrify Paul.

For although the godly are afraid and tremble at the sight of God, Paul must necessarily have been far more afraid when he perceived that the divine power of Christ was set directly against him.