Jan van Ruysbroeck was a Flemmish Mystic who lived in the 13th century. He was reportedly a "fan" of Meister Eckhart - although I'm sure he probably didn't readily admit that publicly. His writings reflect a great deal of Eckhart and Rhineland Theology.
"Man, having proceeded from God is destined to return, and become one with Him again. There where I assert that we are one in God, I must be understood in this sense that we are one in love, not in essence and nature."
One can easily believe that he added the last part to placate church authority, less be accussed of heresy. Still, we can believe that we are one in God.