The Quakers: a religion Richard Dawkins could sign up to
Well, could you?
They have a section for people who do not believe in god at all. The faith (?) (or movement?) is based upon a personal relationship with god. Your god could I suppose by Gaia, or nature, or science... they really would not mind.
They are strong on human rights. They have had many martyrs over the years - people murdered by the so-called great religions for the crime of saying it's OK to doubt.