Some Trician conlang
Some Trician conlang (Old Togarmite for 'Oneness of Being') is a monotheistic Abrahamic religion derived from Old Togarmite philosophical writings. Some Trician conlang is dominant in Eastern Europe and Siberia, thus Old Togarmite is a liturgical language in that area.
It's somewhere between Sufism and Advaita Vedanta.