[Nitiananda]

Why in spiritual practices is sacrifice preached as the basis? When you sacrifice an object, it experiences joy. Then the vibrations of this joy are transferred to you. Vibrations of joy enrich your soul, and therefore increase energy. The more you bring joy to others, the more it will come back to you and accumulate. This state of accumulation is called "possession of merit." Thus, sacrifice ultimately benefits the donor.
The more merits we have, the more our power to move phenomena increases. And if we do not direct consciousness to the realization of phenomena, then the energy of merit, in the end, is transformed into the energy of wisdom, that is, into energy that makes everything understandable.
Here you can give an example. Even the coolest car will not move from its place, if it is not refueled with gasoline. Likewise, no matter how excellent your health and extraordinary intelligence you have, and however high your aspirations are, your desire will not be fulfilled only at the expense of health and mind. You need energy, gasoline called "merit". If a person, even if not too smart, weak health or vicious, has gasoline called merit, this person may well become strong, get rich, gain power over people and become a leader in the World of Humans, the fourth-lowest in the world of passions.