That's the time you must keep on trying
Smile, what's the use of crying?
You'll find that life is still worthwhile
If you just smile
As she sang the "Smile" lyrics with a sad expression on her face, I finally realized why this song has always left me with mixed emotions. I feel joy because it's a beautiful tune and a lovely sentiment. I feel sorrow because it gives a smile more power than it has without Someone behind it to back it up.
Adversity puts the sorrow in Paul's heart along with the yearning for death. As he focuses his thoughts on what God has done for him in sending God's Son, Christ, to companion him, it puts a smile on his lips. Christ within him puts a smile in his heart. Christ empowers him to say "Thanks a lot!" to God, even in prison.
Christ insures a bright future for Paul and the Philippians as they hold fast to their faith in God in times of comfort and times of challenge that lie ahead.