Central to the Pure Land tradition is the figure of the Bodhisattva Dharmakara, the future Amitabha Buddha, who came to exemplify the Bodhisattva ideal and the doctrine of dedication of merit. This merit transference is the source of the vow-power, or other-power, in Pure Land Buddhism.
The Mahayana idea of the Buddha being able to impart his power to others marks one of those epoch-making deviations which set off the Mahayana from so-called … original Buddhism … The Mahayanist accumulates stocks of merit not only for the material of their own enlightenment but for the general cultivation of merit which can be shared equally by their fellow-beings, animate or inanimate. This is the true meaning of Parinamana, that is, turning one’s merit over to others for their spiritual interest.
The rationale for such conduct, which on the surface appears to run counter to the law of Cause and effect, may be explained in the following passage concerning one of the three Pure Land sages, the Bodhisattva Avalokitesvara (Kuan Yin):
Some of us may ask whether the effect of karma can be reverted by repeating the name of Kuan-Yin. This question is tied up with that of rebirth in [the Pure Land] and it may be answered by saying that invocation of Kuan-Yin’s name form another cause which will be right away offset the previous karma. We know, for example, that if there is a dark heavy cloud above, the chances are that it will rain. But we also know that if a strong wind should blow, the cloud will be carried away somewhere else and we will not feel the rain. Similarly, the addition of one big factor can alter the whole course of karma …
It is only by accepting this idea of life as one whole that both Theravadins and Mahayanists can advocate can advocate the practice of transference of merit to others. With the case of Kuan-Yin then, by calling on Her name we identify ourselves with Her and as a result of this identification Her merits flow over to us. These merits, which are now ours, then counterbalance our bad karma and save us from calamity. The law of cause and effect still stands good. All that has happened is that a powerful and immensely good karma has overshadowed the weaker one …
This concept of transference of merit, which presupposes a receptive mind on the part of the cultivator, is emphasized in Pure Land. However, the concept also exists, albeit in embryonic form, in the Theravada tradition, as exemplified in the beautiful story of the Venerable Angulimala. [Note: The life story of the Venerable Angulimala is one of the most moving account in the Theravada canon. After killing 999 persons, Angulimala was converted by the Buddha, repented his evil ways and joined the Order.]