Some religions describe God without reference to gender, while others or their translations use sex-specific terminology. Judaism attributes only a grammatical gender to God, using terms such as "Him" or "Father" for convenience.
God has been conceived as either personal or impersonal. In theism, God is the creator and sustainer of the universe, while in deism, God is the creator, but not the sustainer, of the universe. In pantheism, God is the universe itself. In atheism, there is an absence of belief in God. In agnosticism, the existence of God is deemed unknown or unknowable. God has also been conceived as the source of all moral obligation, and the "greatest conceivable existent". Many notable philosophers have developed arguments for and against the existence of God.
The many different conceptions of God, and competing claims as to God's characteristics, aims, and actions, have led to the development of ideas of omnitheism, pandeism, or a perennial philosophy, which postulates that there is one underlying theological truth, of which all religions express a partial understanding, and as to which "the devout in the various great world religions are in fact worshipping that one God, but through different, overlapping concepts".
In the English language, capitalization is used for names by which a god is known, including 'God'. Consequently, the capitalized form of god is not used for multiple gods (polytheism) or when used to refer to the generic idea of a deity.
The English word God and its counterparts in other languages are normally used for any and all conceptions and, in spite of significant differences between religions, the term remains an English translation common to all. The same holds for Hebrew El, but in Judaism, God is also given a proper name, the tetragrammaton YHWH, in origin possibly the name of an Edomite or Midianite deity, Yahweh.
In many translations of the Bible, when the word LORD is in all capitals, it signifies that the word represents the tetragrammaton.
Ahura Mazda is the name for God used in Zoroastrianism. "Mazda", or rather the Avestan stem-form Mazdā-, nominative Mazdå, reflects Proto-Iranian *Mazdāh (female). It is generally taken to be the proper name of the spirit, and like its Sanskrit cognate medhā, means "intelligence" or "wisdom". Both the Avestan and Sanskrit words reflect Proto-Indo-Iranian*mazdhā-, from Proto-Indo-European mn̩sdʰeh1, literally meaning "placing (dʰeh1) one's mind (*mn̩-s)", hence "wise".
Waheguru (Punjabi: vāhigurū) is a term most often used in Sikhism to refer to God. It means "Wonderful Teacher" in the Punjabi language. Vāhi (a Middle Persian borrowing) means "wonderful" and guru (Sanskrit: guru) is a term denoting "teacher". Waheguru is also described by some as an experience of ecstasy which is beyond all descriptions. The most common usage of the word "Waheguru" is in the greeting Sikhs use with each other:
Waheguru Ji Ka Khalsa, Waheguru Ji Ki Fateh
Wonderful Lord's Khalsa, Victory is to the Wonderful Lord.
Baha, the "greatest" name for God in the Baha'i faith, is Arabic for "All-Glorious".