What does Philippians 4:1 mean?

So, my friends who I care about deeply, the ones I long to see—you're my pride and my joy—stay strong in your trust in the Lord, just like I've been telling you. Philippians 4:1 - Modern Text Bible

(Paul is expressing deep affection for the Philippians, urging them to keep holding on to their faith and commitment to Jesus, because they mean so much to him.)