Noun
The doctrine of those who maintain the existence of two gods or of two original principles (as in Manicheism), one good and one evil; dualism.
Source: Webster's dictionaryIdel characterizes this metaphysical point of view as "ditheism", holding that there are two aspects to God, and the process of union as "theoeroticism". Source: Internet
While bitheism implies harmony, ditheism implies rivalry and opposition, such as between good and evil, or bright and dark, or summer and winter. Source: Internet