"we believe in and confess one God, even if in a different way, and we praise and worship Him daily as the Creator of time and the ruler of this world. . . .
". . . For God knows [that] we love you purely for the honor of God and wish for your salvation and well-being in the present and in the future life, and with heart and mouth beseech God to conduct you, after a long course in this life, into the blessed bosom of the most holy Patriarch Abraham."
Pope Gregory VII to an-Nasir ibn Alnas, the Hammadid emir of Bugie (Béjaïa), in 1076, as quoted by Peter Dinzelbacher, in his "Kritische Bemerkungen zur Geschichte der religiösen Toleranz und zur Tradition der Lessing'schen Ringparabel," Numen 55 (2008): 18 (1-26), which cites "Registrum 3, 21, Monumenta Germaniae Historica, Epp. Sel. 2, 287 f." (this passage on p. 288). This, Dinzelbacher (citing pp. 545 ff. of The Crusades: an encyclopedia) points out, is the same Gregory who "planned a crusade." Mere diplomacy-speak designed to secure the safety of Christians living in Bugie (citing Cowdrey, Pope Gregory VII, 1073-1085 (Oxford, 1998), 492 ff.; but "more positively" Gfrörer, Pabst Gregorius VII. und sein Zeitalter IV (Schaffenhausen, 1859), 581 ff., and Medieval Christian perceptions of Islam, ed. Tolan (New York, 2000))? Maybe. "but obviously Gregory himself was already able to conceive of a kind of natural religion."
Nonetheless, I must not give the impression that Dinzelbacher, at least, would rehabilitate "'the'" Middle Ages more generally. For "Neither Wolfram von Eschenbach nor Ramon Llull nor even Gregory VII" had any real impact, but were, rather, "untypical of their epoch". Much more typical was, supposedly, Peter Comestor, who exclaimed, "funde sanguinem inimicorum" ("Shed the blood of the enemies of Christ") (18). Indeed, it was only with the Renaissance, early modernity (which recovered the Stoic "conception of the equality of all men"), the Wars of Religion, and the Enlightenment (which stressed "that reason is common to all men") that a commitment to tolerance began to take hold (19 ff.).
I began with Dinzelbacher's German, but here's the Latin, taken from MGH above:
"unum Deum, licet diverso modo, credimus et confitemur, . . . eum creatorem seculorum et gubernatorem huius mundi cotidie laudamus et veneramur.
". . . Scit enim Deus, quia pure ad honorem Dei te diligimus et salutem et honorem tuum in presenti et in futura vita desideramus atque, ut ipse Deus in sinum beatitudinis sanctissimi patriarchę Abrahe post longa huius vitę spatia te perducat, corde et ore rogamus."