Not happiness, but true joy. Happiness is too circumstantial. Dependent on what's happening in your life. An "under the circumstances" viewpoint/location. A location where Mary Ann Frazier says no Christian should reside. Christ's beloved should rise above their fleeting circumstances and experience deep joy based on their relationship with Him.
You will show me the path of life;
In Your presence is fullness of joy;
At Your right hand are pleasures forevermore. (Psalm 16:11)
The "lasting" answer is found in that verse. True joy, in all its fullness, regardless of one's circumstances, is found in the Lord's Presence. A question and a verse worthy of meditation.