For forms of government let fools contest;
Whate'er is best administer'd is best:
For modes of faith let graceless zealots fight;
His can't be wrong whose life is in the right.
In Faith and Hope the world will disagree,
But all mankind's concern is Charity:
All must be false that thwart this one great end,
And all of God that bless mankind or mend.
Alexander Pope, Essay on Man, EPISTLE III: Of the Nature and State of Man, With Respect to Society
Or, to quote a South Asia poet I have quoted before:
mazhab thoe buss mazhab-e-dhil hai; baaqee sub gumraahee hai
[the only (true) creed is the creed of the heart; all else is heresy]