Paul sets an example of living in joy in the book of Philippians.  We can find 5 “Happiness Habits” that Paul lives out in Philippians 3.

Our opening verse is philippians 3:3, The Living Bible Translation & Message version:

“We Christians glory in what Christ Jesus has done for us and realize that we are helpless to save ourselves.”  Philippians 3:3 

“We couldn’t carry this off by our own efforts, and we know it”  Philippians 3:3 (MSG)
Paul relaxes in the fundamental truth of God’s grace. He finds joy every day, regardless of the problems that swirl around him, in the fact that Jesus came to love him, to save him, and to have a relationship with him. He was no longer dependent on anything that he, as a devout Jew, had done for God, but rather, on what God had done for him. 

Happiness Habit: Wake up every day with a heart spilling over with gratitude for the fact that God’s love for you isn’t based on what you’ve done but on who He is.