Yes it is possible to be spiritual without subscribing to a mainstream religion. By understanding basic spiritual principles within religion, one can skip the drama and dogma and get right to the heart of the matter, to better understand our own selves and to nurture a better understanding of right relation with those around you. Through dedicated spiritual practices like meditation and yoga, it's possible to relax the mind enough to actually find joy in life. After acquiring an understanding of our sacred relationship to the earth, one can also nurture a positive relationship with the planet. This is a very important area, as human life is facing planetary earth challenges that might lead to planetary unsustainability.