12 Dear friends, you always followed my instructions when I was with you. And now that I am away, it is even more important. Work hard to show the results of your salvation, obeying God with deep reverence and fear. 13 For God is working in you, giving you the desire and the power to do what pleases him.
14 Do everything without complaining and arguing, 15 so that no one can criticize you. Live clean, innocent lives as children of God, shining like bright lights in a world full of crooked and perverse people. 16 Hold firmly to the word of life; then, on the day of Christ’s return, I will be proud that I did not run the race in vain and that my work was not useless. 17 But I will rejoice even if I lose my life, pouring it out like a liquid offering to God, just like your faithful service is an offering to God. And I want all of you to share that joy. 18 Yes, you should rejoice, and I will share your joy.
Paul is saying that my faithful service is done in reverent and fearful obedience. But God is my partner in my obedience. He not only gives me the desire to obey, he gives me the power to obey, and the end result of that is joy. Joy comes as I walk in obedience that is coupled with faithful service. That’s where I find joy.
He also makes it clear that there is work involved. We don’t just walk in obedience as a natural response. We have to make the effort. But what a promise! When I make the effort, it is God who is also working–making the effort–within me!