As C_A said, religion is a paved path. It is built with dogma to establish the hierarchy between the member and the deity involved. It outlines a path, with restrictions and requirements to keep you on that path, and control your interaction with the divine. Many also attempt to take control of your money, through tithing.
Spirituality, on the other hand is a self-defined journey, focused on your own needs and beliefs, rather than a prefabricated litany of checks and balances.
I'm a Christian; I abhor the Christian churches. I'm a Gnostic, not because I'm some kind of expert on the Gnostic gospels, the Dead Sea Scrolls, and the Library at Hammurabi, but because I believe all spiritual knowledge starts within.
I believe I was created in G-d's image, in the sense that all living things have a divine spark, where they are all connected to each other and the divine. While I believe in the teachings of Jesus, I'm not sold on the idea that he was the son of G-d, except as a metaphor for the idea that we are all children of G-d, and the difference is that very realization.
Christian religions would never accept my position, but why do I have to let someone else define my inner spiritual beliefs?