What is the relationship between "progress" and "joy"?

The intimate connection between progress and joy in the faith is clearly apparent in the text. The two nouns progress and joy are bound together by the same denominator under one article. There is a close relationship between faith and joy (2 Corinthians 1:24). Faith is not a theory, but involves a confident outlook on life. The stronger it grows, the safer and happier one is likely to feel. And that is what the apostle is mainly concerned with. He himself knows this joy (Philippians 1:18), and he wants to foster it among the Philippians too (Philippians 2:18; Philippians 3:1; Philippians 4:4). This requires progress and growth in the faith. In the next chapter, therefore, Paul also calls upon the believers to be united in love and humility. The whole of the epistle is aimed at this intended growth and joy in the faith. Paul realizes that by way this letter, his being in chains needs to bear fruit in Philippi.¹