John Calvin Commentary Philippians 3:7

"Howbeit what things were gain to me, these have I counted loss for Christ." — Philippians 3:7 (ASV)

What things were gain to me, he says that those things were gain to him, for ignorance of Christ is the sole reason why we are puffed up with vain confidence. Therefore, where we see a false estimate of one’s own excellence, where we see arrogance, where we see pride, there let us be assured that Christ is not known.

On the other hand, as soon as Christ shines forth, all those things that formerly dazzled our eyes with a false splendor instantly vanish, or at least are devalued. Accordingly, those things which had been gain to Paul when he was still blind, or rather, had deceived him with an appearance of gain, he acknowledges were loss to him when he was enlightened. Why loss? Because they were hindrances to his coming to Christ. What is more harmful than anything that keeps us back from drawing near to Christ? Now he speaks chiefly of his own righteousness, for we are not received by Christ, except as naked and emptied of our own righteousness. Paul, accordingly, acknowledges that nothing was so injurious to him as his own righteousness, because it shut him out from Christ.