Divinity within will not allow the mind to dwell on negative thoughts and emotions, fears, desires, jealousy and hatred, or to be controlled and distracted by external influences. With the mantra, we have a tool for redirecting the energy of the mind within so that we can reclaim our inner composure. Mantras can help us break up deep-seated mental and emotional patterns, conditioning and traumas even from previous lives.In the beginning, mantras promote sattva guna to create the proper balance in the mind, removing toxins from the body, and neutralizing the residual energies of rajas and tamas or agitation and inertia from the subconscious. The second stage consists of going beyond the mind-body complex and all of its conditioning, even that of sattva guna, to pure awareness.
Bhakti Yoga, the Yoga of devotion is chanting, singing the Divine mantras like Namah Sivaya or the Hare Krishna. Devotion develops into love of the divine.
Jnana Yoga, the Yoga of knowledge, focuses on Self-revealing mantras like So-oo-oo-ham. Om is the mantra of Self.
Karma Yoga is performance of rituals, like pujas and yajnas. Mantras empower and sanctify them. Service (seva) to others is best done repeating a mantra.
Kundalini Yoga is to move energy of vibrations coherently by placing Sanskrit letters in the petals on the body of lotuses.
Nada Yoga Nada is the inner power behind the mantra. The outer mantra works to awaken the inner. Then the nada assumes the form of mantra, and repeats it, which is held in our inner sound current. This yoga is listening to the music within; like a bell, a drum, a flute, the ocean etc, which are in the intelligence of space.
The main insight in all mantra paths is that reality consists of vibrations of energy in space and time. Consciousness spins the space, time and matter (a form of energy). It alone is the state of pure calm of unity.
Thanks Guru Amritanand jee.