The Philippians were already in the habit of obeying, so Paul encourages them to continue in it even more so in his absence. They should fight for obedience - with fear and trembling - because it is God who works in and through them for his purposes.

As such, there is no room for complaining. By serving and obeying with joy, God’s people stand as bright stars - lights of the world. We must hold on tightly to the Word’s of Christ, obeying his commands as disciples. In doing this, our discipleship (and the labor of our mentors) is not in vain.

Upon this foundation, Paul can say that even if he dies he can rejoice in their discipleship and know that his labor was not in vain!