If you want happiness, then you must learn how to love God. You are trying to love somebody, but you are being frustrated, foiled. Because except God, nobody is loving object. And if you love God, then naturally you love everything, because God is everything. The example is that if you pour water on the root of the tree, it goes everywhere -- to the twigs, to the leaves, to the flowers, everywhere. But if you pour water on the leaf, it is localized; it does not spread. So we are manufacturing, inventing, so many humanitarian work, welfare work, but still, people are unhappy. Why? Because it is pouring water on the leaf, not on the root.

Srila Prabhupada
Lecture | London, 1971