In plain words
A man takes a liking: ‘I must smoke a cigarette.’ Or, ‘I must drink a coffee, I must drink liquor.’ When there are such desires, and we give them up and keep those desires under control, the power that was flowing out on them merges into the power of will. Suppose every man has some twenty or thirty desires. However many of these desires you reduce, the power that was flowing out on those desires merges into the power of will and strengthens it. So if you develop the power of will in this way, you can become even Indra. One can make a success of whatever one has resolved. This power of will alone is the cause of every success. That is why all the ancient ṛṣis, who recognised this secret, kept every desire and every longing under control in the name of Vairāgya. The more desires decrease, the more the power of will grows. So we must try to reduce our desires little by little.
We must turn this power of will towards God. Even when we have the power of will, if we do not turn it towards God, this power of will becomes useless. We think of every person too as an Instrument, a tool. But this tool too must be fit for the work. Even if the person using it is very strong, if the crowbar has no sharpness, this strength too becomes useless. That tool too must be strong and very sharp. Only then is one's strength too put to good use. However much strength a man has, if the tool is not as it should be, he cannot get any work done at all with that tool. In the same way, however mighty the power of will may be, if one's feelings do not turn into feelings for God, this power of will becomes useless. So along with the power of will we must nourish the power of action, and along with the power of action the power of Jñāna. When we develop good thoughts in this way, there is nothing at all in this world we cannot achieve. We can achieve everything. So we must turn the power of will in us into good thoughts. The power of thoughts: even when a man dies, thoughts do not die. They are undying. They are immortal. So we must nourish our thoughts as right thoughts.