Mantra yoga means "union by voice or sound". This form includes the rhythmic repetitions of specific sounds, chants, or mantras. The practitioner repeats the syllable, word or phrase continually, sometimes for weeks, months or years on end. Certain syllables are believed to posses healing potential for specific purposes. (for example see Transcendental meditation where a mantra is assigned for individual use.)

The word mantra is related to manas (the mind). Yoga means to unite with our Origin. Mantra Yoga would then mean to unite using the tool of mantra. This process is called Concentration and Meditation. A mantra is a sound or word.

It is generally used to help focus the mind on a single thought until thoughtless Beingness is established. As a tool to achieve Stillness, the mantra is to be discarded at the moment Stillness is achieved.

Mantras are sometimes also applied to change circumstances, to regain a healthy condition for example. Those mantras are specially formulated to carry a certain vibrational power. For such purposes it is important that the proper pronunciation is also imparted.

Japa

Repetition of a name of God may be used as a mantra and is then called japa.

A mala is usually used for automatic counting but, when used in connection with japa, it is more for anchoring the mind and make it more rhythmic. Japa and mala are for a similar purpose as the stick given to an elephant in India when lead through narrow streets where merchants display their goods on tables. Without carrying the stick in his trunk, the elephant will move its trunk to the left and right knocking off the display, but, when given the stick the elephant will carry the stick straight ahead.
In order to keep our trunk - the mind - still, we are practicing meditation, japa, or any other spiritual technique. One traditional name for the practice of japa is Rama.

However, Christ or any other name of God is fine as long as the association is there. If the association is not there, any other mantra may produce the same result. Japa should be repeated constantly, this technique, more than any other, is the exact equivalent to the first commandment of the Bible: "You shall love God with all your heart, mind and soul." What else would it be if we were to concentrate fully on God - with all our heart, mind and soul?

Bija

There are also bija-mantras which may be seen as keys with which one might address a certain chakra (energy center in the spine and brain) for example.

The main keys to the seven chakras are Lam, Vam, Ram, Yam, Ham, Ksam, Bam (or OM). Each chakra addressed by one of the major mantras also includes other bijas.