John Calvin Commentary Acts 24:16

"Herein I also exercise myself to have a conscience void of offence toward God and men always." — Acts 24:16 (ASV)

And in this I study. There is no sharper goad to urge people forward, with all desire to lead a godly and holy life, than the hope of the final resurrection, as Scripture teaches in many places. Therefore, when Paul effectively exhorts the people anywhere, he calls them to remember it (Philippians 3:20).

For this reason, it is not without cause that he says in this place that, relying on this faith, he has endeavored to live purely before God and righteously among men. Indeed, an evil conscience serves as a thousand witnesses to accuse people of spiritual dullness, so that they may conclude with certainty that they do not earnestly and thoroughly believe in eternal life, for which they never truly long.

He calls it a conscience απρόσκοπον (that is, without offense), where the servants of God strive to remove all obstacles that hinder their course. And he describes two parts of the conscience. For there is a certain inward sense or feeling that perceives God alone, and from this comes the faithfulness and integrity that we show towards others.

Furthermore, when he says that he has constantly pursued godliness in worshipping God as well as just dealings among men, he indicates to us that those who truly hope for the final resurrection are those who are never weary of doing good. For this word "always" signifies perseverance in a right course.