I admit that history is filled with religious wars, but let us be careful here, for it is not the multiplicity of religions which has produced these wars, but the spirit of intolerance stirring those who believed themselves to be in a dominant position.

[J’avoue que les histoires sont remplies des guerres de religion : mais, qu’on y prenne bien garde, ce n’est point la multiplicité des religions qui a produit ces guerres, c’est l’esprit d’intolérance, qui animoit celle qui se croyoit la dominante.]

Charles-Lewis de Secondat, Baron de Montesquieu (1689-1755) French political philosopher

Persian Letters [Lettres Persanes], Letter 86, Usbek to Mirza (1721) [tr. Healy (1964), Letter 85]
    (Source)

(Source (French)). Alternate translations:

I confess histories are full of religious wars: but do not let us take the thing wrong; it was not the diversity of religious that occasioned these wars; it was the untolerating spirit of that which thought she had the power in her hands.
[tr. Ozell (1760 ed.)]

I acknowledge, that history is full of religious wars: but we must take care to observe, it was not the multiplicity of religions that produced these wars, it was the intolerating spirit which animated that which thought she had the power of governing.
[tr. Floyd (1762), Letter 85]

I acknowledge that history is full of religious wars: but we must distinguish; it is not the multiplicity of religions which has produced wars; it is the intolerant spirit animating that which believed itself in the ascendant.
[tr. Davidson (1891)]

I acknowledge that history is full of religious wars ; but it is an indisputable fact that these wars have not been produced by the multiplicity of religions, but rather by the intolerance of the dominant creed.
[tr. Betts (1897)]

I admit that history is full of wars of religion; but on this point we must be very careful; it is not the multiplicity of religions that produced these wars, but the spirit of intolerance animating the religion that believed itself to be dominant.
[tr. Mauldon (2008), Letter 83]

I admit that history is full of wars of religion. But one must be careful here: these wars were not caused by a multiplicity of religions, but rather by the spirit of intolerance shown by the dominant religion's believers.
[tr. MacKenzie (2014), Letter 85]