Yoga is a generic name for any discipline by which one attempts to pass out of the limits of one's ordinary mental consciousness into a greater spiritual consciousness.
Detachment is not indifference. it is the prerequisite for effective involvement. Often what we think is best for others is distorted by our attachments to our opinions. We want others to be happy in the way we think they should be happy. It is only when we want nothing for ourselves that we are able to see clearly into others needs and understand how to serve them.
Meditation is the dissolution of thoughts in Eternal awareness or Pure consciousness without objectification, knowing without thinking, merging finitude in infinity.
The yoga we practice is not for ourselves alone, but for the Divine; its aim is to work out the will of the Divine in the world, to effect a spiritual transformation and to bring down a divine nature and a divine life into the mental, vital and physical nature and life of humanity. Its object is not personal Mukti, although Mukti is a necessary condition of the yoga, but the liberation and transformation of the human being. It is not personal Ananda, but the bringing down of the divine Ananda - Christ's kingdom of heaven, our Satyayuga - upon the earth.
Anything that is secret and mysterious in this system of Yoga should be at once rejected. The best guide in life is strength. In spirituality, as in all other matters, discard everything that weakens you. Have nothing to do with it. Mystery-mongering weakens the human brain. It has well-nigh destroyed Yoga, one of the grandest of sciences