A lot of Druids believe in at least one god of nature. A lot of people consider Druidic beliefs as being more old-fashioned than the religions of Clerics and city dwellers, and even consider Druidic religious beliefs as being the "Old Faith". Your Druid might worship a god associated with the place you select for the Circle of the Land or when you select for the Circle of the Moon, you could worship a moon goddess such as Selune and an idol associated with the animal you typically change into. Some Druids worship nature in general.