St. Augustine: Gathering to worship the one supreme and true God

This Heavenly city, while it sojouns on earth, calls citizens out of all nations, and gathers toether a society of pilgrims of all languages, not scrupling about diversities in the manners, laws, and institutions whereby earthly peace is secured and maintained, but recognizing that, however various these are, they all tend to one and the same end of earthly peace. It therefore is so far from resinding and abolishing these diversities, that it even preserves and adapts them, so long only as no hindrance to the worship of the one supreme and true God is thus introduced. 

-- Saint Augustine, The City of God, book 19, paragraph 17