You have to grow from the inside out. None can teach you, none can make you spiritual. There is no other teacher but your own soul.
The soul which is free from the defect of karma gets to the highest point of the universe, knows all and perceives all, and obtains the transcendental bliss everlasting.
One who identifies himself with his soul regards bodily transmigration of his soul at death fearlessly, like changing one cloth for another.
O Lord of all, hail unto Thee! The Soul of all, causing all acts, enjoying all, all life art Thou! Lord of all pleasure and delight!
True religion is not talk, or doctrines, or theories, nor is it sectarianism. It is the relation between soul and God.
Since, O Mazda, from the beginning, Thou didst create soul and body; mental power and knowledge and since Thou didst place life within the corporeal body and didst bestow to mankind the power to act, speak and guide, you wished that everyone should choose his or her own faith and path freely.
The soul that is attached to anything, however much good there may be in it, will not arrive at the liberty of Divine union. For whether it be a strong wire rope or a slender and delicate thread that holds the bird, it matters not, if it really holds it fast; for until the cord be broken, the bird cannot fly.
When an exalted soul realises that all sentient beings are one in relation to the Supreme – that is, that all beings are the minute parts of the One – how shall he have any more delusion and what grief will come to him?
For the soul there is neither birth nor death at any time. He has not come into being, does not come into being, and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when the body is slain.

