Oxford English Dictionary - The religious belief or philosophical theory that God and the Universe are identical (implying a denial of the personality and transcendence of God); the doctrine that God is everything and everything is God.
Grolier's Encyclopaedia - Pantheism is the belief that everything is divine, that God is not separate from but totally identified with the world, and that God does not possess personality or transcendence.
Philosophy of Pantheism - The word pantheism derives from the Greek words pan ('all') and theos ('God'). Thus pantheism means 'All is God'. Pantheism is the religious belief that Nature is divine (God) and we humans are part of the One, interconnected whole. It is in realizing our connection to the One Universe (Nature, God, Brahman, Tao, Space) that we find truth, spiritual fulfillment and solace. Pantheists usually deny the existence of a personal God (theism) and creationism (a separate God who created the world from nothing).http://opensite.org/Society/Philosophy/Religion/Pantheism/
Pantheism is the worldview held by most Hindus, many Buddhists, and other New Age religions. It is also the worldview of Christian Science, Unity, and Scientology.
One major shortcoming with Pantheism as far as religion is concerned, it really doesn't provide an answer for the problem of evil in the world, as other religions do.