The Apostle's thought in what has been said thus far rests entirely on this last point. It is natural to understand it here also. Yet since this zeal proceeded from faith and from love for the faith, the Apostle may also have understood by the good work the work of salvation through faith in the Lord. He did not mean it exclusively, but insofar as it was expressed in the charitable work that distinguished the Philippians and animated it.
The Apostle expresses his specific desire for their progress in the Christian life and in the work of salvation below, in verses 9-11. Here everything concerns one thing, their known fellowship in the gospel.
The day of Jesus Christ is His Second Coming. Every Christian, according to the word of the Lord Himself, must expect it from hour to hour, and prepare to meet Him by multiplying those good works that are most at hand and familiar to him.
Since the Philippians had already begun to assist the gospel by a special inspiration from God, the Apostle judges from this source of their good work. He expresses confidence that it will continue until the day of the Lord. God will give them strength to remain constant in it and "to bring it to the Lord at His coming as a pure sacrifice" (St. John Damascene).
There is nothing improper in his limiting himself here to this one thing. Of the sum of works pleasing to God, not everyone can and must do everything. Let each person please God by that for which he is most fit. This applies both to each person and to whole communities.
The Philippians proved especially suited for the work of assisting the gospel, and God inspired them for it. The Apostle expresses his benevolent confidence that He will not cease inspiring them for it to the end. In this lies their salvation.
But what is the connection between this text and the preceding one? In it he expresses the reason why the Apostle especially rejoices in his prayers for the Philippians and so zealously thanks God for their remembrance.
If they had done their good work once or twice and then stopped, it would have disappeared in the sum of other deeds. It would have been forgotten even by them and would have left no trace. There would be no reason to mention it and set it so high.
But it became especially precious in the Apostle's eyes because of his confidence that, by God's inspiration and assistance, they would not cease to practice it until the end. With it they would meet the Lord. Therefore it would be for them a bridge into paradise. This gladdened the Apostle and called forth his thanksgiving to God.
St. Chrysostom saw in the Apostle's words a subtle indication of the relation between grace and freedom. He expressed it in this way: "See how he teaches them humility. Since he had attributed great praise to them, lest some passion proper to man take hold of them, he immediately teaches them to refer both the past and the future to Christ.
"How does he do this? He did not say, Being confident that as you began, so you will also complete. But what did he say? 'He who began a good work in you will complete it.' Yet he does not deprive them of virtues. For it is no small praise that God works in someone.
"If He is not a respecter of persons, as indeed He is not, but helps us in good works according to our disposition, then the reason why He inclines toward us lies in us. Thus the Apostle does not deprive them of praise in this way either.
"For if God acted unconditionally, if He moved us like wood and stones and did not require our participation, nothing would prevent Him from acting also in pagans and in all people. Therefore in the words, 'God will complete it,' there is again praise for them. They drew to themselves the grace of God, which helped them rise above human nature.
"On the other hand, this too is praise, that you have such virtues as are not the work of man, but require divine assistance. If God will complete it, then not much labor will be required from our side. We must hope that with His help we shall accomplish everything easily."