Kindness comes back like a boomerang to those who are kind. Perhaps, its return takes years. Perhaps, the kindness returns from a different direction than that which we sent out kindness. But it will return. It is never lost.
If we have not developed a reservoir of spiritual wealth, no amount of money is likely to make us happy. Spiritual wealth provides faith. It gives us love. It brings and expands wisdom. Spiritual wealth leads to happiness because it guides us into useful or loving relationships.