I would like to know if meditation and concentration is about controlling the mind and directing it toward God or other things and is the world made of "mind stuff". Can we also use these techniques to acquire materials needs as well as grow spiritually?
Thank you for your questions. Yogananda defined meditation as concentration on God in one of his eight manifestations: light, sound, wisdom, power, peace, calmness, love, and bliss.
It is of course possible to concentrate on other things besides God — indeed, we should try to give full concentration to whatever we do in life. However, concentration without God is not meditation, and taken alone, may not give us satisfactory results.
Is the world made of “mind stuff”? Yes, but the not stuff of our minds! Yogananda often said that God is dreaming our existence. The more we tune more into God’s consciousness, the larger the impact we can have on this world.
As for your last question, yes: the laws of true spiritual success and true material success are the same. You may be interested in read articles on this subject from Swami Kriyananda’s course, Success and Happiness through Yoga Principles.
May God ever bless your efforts!