Gayatri mantra is a Vedic prayer. It is a universal prayer that can be used by any person, belonging to any country, irrespective of race, religion, or sex. This book includes the symbolism of Om and the Gayatri, the scriptural references where they are mentioned, as well a detailed instruction on how to perform the Sandhya rituals. Text for the rituals is in Sanskrit with transliteration, and English translation.
The important thing is how much less you think of the body, of yourself as matter -- as dead, dull, insentient matter; how much more you think of yourself as shining immortal being. The more you think of yourself as spirit, the more eager you will be to be absolutely free from matter, body and senses. This is the intense desire to be free.
-Swami Vivekananda