Could someone explain to me:
- What is the role of yoga & meditation in Hinduism - what is its purpose and relation to God?
- And how is Hinduism's yoga/meditation practice and purpose different from Buddhist practice and purpose?
I am following roughly the book 'The Serpent Power' by Arthur Avalon (Sir John Woodruffe).
The reason for us not seeing anything beyond the material world is because our physical mind which has neural correlates with the brain is incapable of seeing beyond the material world.
Hindu scriptures say that there is another mind, a spiritual mind or pure mind, which is indeed capable of seeing beyond the material world. This spiritual mind is connected with Chakras or energy centers located inside the sushumna channel in our spine.
There are broadly two methods of developing this spiritual mind.
One method is to take help from Divine Beings. Bhakti Yoga, Mantra Yoga, Raja Yoga (partially), Patanjali's Yoga (partially) are some of the methods that take help of Divine Beings.
The other method is to decline any Divine help and do it with one's own effort. Jnana Yoga and Buddhism claim to follow the second method. In reality many Jnana Yogis and Buddhists do take help of Divine Beings.
Yoga is the union of the subject and the object. Meditation is the ways, the means, to attain that. Through meditation we learn to control the mind. We are not aware of the spiritual world because since our birth our minds have been constantly bombarded by sensory experiences. To see the bottom of a pool of water, the water must be still, there cannot be any waves on the surface of the water. If you teach your mind to stop accepting sensual stimuli, then the spiritual world will opne up by itself. Swami Vivekananda said "Control the mind, cut of the senses, then you are a Yogi; after that, all the rest will come...." Our minds need to be stilled so that we can perceive what is below the surface. Vivekananda also said " This going outwards must be stopped [the mind looking only towards the senses]. This is what is meant by turning the eyes inwards, and then alone the glory of the Lord within will be seen."
Vivekananda's book "Raja Yoga" also has his translation of Patanjali's Yoga Aphorisms.
There is no philosophical difference between Mahayana Buddhism and Advaita Vedanta. Buddha said - find out for yourself. Meditate. Find out yourself if there is a difference by meditation, not argumentation.