François Bernier, “Lettre à Monsieur Chapelain” (1667).
When I said to them [the Indians] about this, that in the cold countries it would be impossible to observe their law [on bathing] during the winter, which was a sign that it was a pure human invention, they gave me this rather amusing response: that they did not claim that their law was universal; that God had made it for them and it was for that reason that they could not receive a foreigner into their religion; that for the rest, they did not claim at all that our [religion] was false; and that it might well be that it was good for us and that God had created different paths to go to heaven, but that they did not wish to accept that our [religion] being valid for all of the earth, theirs was nothing more than a fable and pure invention.