Saint Meister Eckart's non-dual preachings strikingly sound exactly like verses from Advaitic texts.
"The soul must be stripped of all her forms and clothed in her formless form, which is God Himself. When the soul loses her own name and her own form, she is absorbed into the infinite abyss of the divine nature."
— Meister Eckhart, Sermon 52
Eckhart is even using the same terminology/language as the Vedantic texts. The emphasis on "name" and "form" is exactly what even Vedantic texts describe, the "nama" and "rupa" as the qualities to be negated/stripped to know the truth.
My fav christian non-dualist after Christ himself.