The head of the worldwide Anglican communion told attendees at a lecture at St Martin-in-the-Fields in Trafalgar Square: "All human language about God is inadequate and to some degree metaphorical.
"God is not a father in exactly the same way as a human being is a father. God is not male or female. God is not definable.
"It is extraordinarily important as Christians that we remember that the definitive revelation of who God is was not in words, but in the word of God who we call Jesus Christ. We can’t pin God down."
Professor of Christian history Diarmaid MacCulloch backed Archbishop Welby’s statement, telling The Times that the reason God has been perceived as male is due to "patriarchal assumptions" of early Christian societies of Greece and Rome.