The meaning of dharma translated in English is not adequate. Dharma means which cannot be given up. The so-called dharma, or religion . . . suppose I am Hindu and somebody is Christian. This is called faith. The dictionary meaning is, "Religion is faith." So faith can be changed. "I believe in Christian religion," so it can be changed next day—I accept Hindu religion or Muslim religion. But actually, dharma cannot be changed.
The example is given: just like water. The characteristic of water is liquidity. So you cannot change this quality of water, liquidity. Similarly, stone is solid. You cannot change the quality of solid. This unchangeable quality is called dharma. That is really Sanskrit significance. Now, you can argue that water sometimes becomes solid, ice. That is conditional. Under certain condition, the water becomes solid, but immediately it begins to become liquid. It melts. The tendency is to melt, not to keep solidity. So this consistency of keeping water in liquid form is called dharma.
So as everything has got some particular characteristic, similarly we living entities, we must have some particular characteristic. And what is that? That is dharma and jñāna, to understand. Jñāna means knowledge: "What I am? Am I this body, or I am something else?"