John Calvin Commentary Philippians 1:11

"being filled with the fruits of righteousness, which are through Jesus Christ, unto the glory and praise of God." — Philippians 1:11 (ASV)

Filled with the fruits of righteousness. This now belongs to the outward life, for a good conscience produces its fruits by means of works. Therefore, he desires that they may be fruitful in good works for the glory of God. Such fruits, he says, are by Christ, because they flow from the grace of Christ. For the beginning of our well-doing is when we are sanctified by his Spirit, for the Spirit rested upon him, that we might all receive of his fullness (John 1:16).

And as Paul here draws a comparison from trees, we are wild olive-trees (Romans 11:24) and unproductive, until we are grafted into Christ, who by his living root makes us fruit-bearing trees, in accordance with that saying (John 15:1), I am the vine, you are the branches. He at the same time shows the purpose—that we may promote the glory of God. For no life is so excellent in appearance as not to be corrupted and become offensive in God’s sight, if it is not directed towards this object.

Paul’s speaking here of works under the term righteousness is not at all inconsistent with the gratuitous righteousness of faith. For it does not immediately follow that righteousness exists wherever there are the fruits of righteousness. Indeed, there is no righteousness in God’s sight unless there is a full and complete obedience to the law, which is not found in any of the saints. Nevertheless, they do bring forth, according to the measure, the good and pleasant fruits of righteousness. This is because, as God begins righteousness in us through the regeneration of the Spirit, what is lacking is amply supplied through the remission of sins, in such a way that all righteousness, nevertheless, depends on faith.