John Calvin Commentary Acts 23:17

"And Paul called unto him one of the centurions, and said, Bring this young man unto the chief captain; for he hath something to tell him." — Acts 23:17 (ASV)

Calling to him. Paul was not so desirous of life, but he would have hastened to die, if the Lord had thought it good for it to be so; but because he knows that he serves Christ on the condition that he may live for Him no less than die for Him, he does not neglect to avoid the danger which was revealed to him. And though he is fully persuaded that God is the keeper of his life, yet he does not wait until God extends His hand from heaven to work a miracle, but instead uses the remedy which is offered him, not doubting at all that it is appointed by God.

Thus all ministers of Christ must act, so that, being equipped with invincible constancy, as far as their calling requires, they do not fear danger, and yet do not cast themselves away through rashness. Let them call upon the name of the Lord cheerfully, even in the midst of pikes; and yet let them not despise the help that is offered. Otherwise, they will be wronging God, because they are not only unmoved by His promises but also despise the means which He has appointed for their deliverance.