In the chapter on effort in Guide to the Bodhisattva’s Way of Life Shantideva advises us that before we commit ourself to engaging in a practice we should investigate it carefully to see whether it is suitable and whether we can sustain it; but once we have committed ourself to it we should never turn back but continue until we attain the final result. Switching from one practice to another unrelated practice not only prevents us from fulfilling our wishes in this life, but also makes it difficult for us to accomplish our goals in future lives. Moreover, it is often the cause of breaking our commitments and severing precious relationships, such as those that exist between Guru and disciple, and between spiritual friends.
We must be careful not to misunderstand the effort of non-satisfaction. Practicing this effort does not mean that we should become dissatisfied with our tradition or with our main practice, and try to follow many different traditions or mix together many different practices. Every Teacher and every tradition has a slightly different approach and employs different methods. The practices taught by one Teacher will differ from those taught by another, and if we try to combine them we shall become confused, develop doubts, and lose direction. If we try to create a synthesis of different traditions we shall destroy the special power of each and be left only with a mishmash of our own making that will be a source of confusion and doubt. Having chosen our tradition and our daily practices we should rely upon them single-pointedly, never allowing dissatisfaction to arise. At the same time as cherishing our own tradition we should respect all other traditions and the right of each individual to follow the tradition of their choosing. This approach leads to harmony and tolerance. It is mixing different religious traditions that causes sectarianism. This is why it is said that studying non-religious subjects is less of an obstacle to our spiritual progress than studying religions of different traditions.
Once we have decided which tradition to follow and which practices to do, we should engage in them wholeheartedly with a joyful mind. This is the power of joy. Whether we are listening to Dharma teachings, reading Dharma books, reciting prayers, contemplating, or meditating, we should do so with a light and happy mind, like a child at play. If we enjoy a practice we shall naturally have enthusiasm for it. (Geshe Kelsang Gyatso, Understanding the Mind: an Explanation of the Nature and Functions of the Mind, pp. 161-162, © 1993, 1997, 2002)