In verse 3, the psalmist says of the righteous man (one who follows God):
"He is like a tree
planted by streams of water
that yields its fruit in its season,
and its leaf does not wither.
In all that he does, he prospers."
Although I aim to follow God, I don't always feel very prosperous. Usually I evaluate prosperity in terms of "externals" - house, health, career, marriage, kids. However, I saw prosperity in a different light when I read the study note in my Bible:
A tree bears fruit, not for itself, but for others;
thus, when the faithful prospers, it is not for himself, nor is the prospering even necessarily material, but he succeeds in bringing benefit to others.
What an amazing God we serve, who can use brokenness to bring true prosperity.