Mechtild of Magdeburg was born around the year 1207, most likely into a noble family in northern Germany. At the age of 12 she had an ecstatic experience, along the lines of Saul on the road to Damascus, which she described as seeing "all things in God and God in all things."
When she was in her twenties she joined a religious order, became a nun. She continued to have mystical visions. She had a spiritual advisor who encouraged her to write about those experiences. The book took most of the rest of her life, and was called “The Flowing Light of the Godhead”. It described the intimate union between God and the human soul in terms of a sacred marriage. Much of the book reads as love poetry, and after her death, her writing came to be considered amongst the most beautiful written in the German language. Her work was an influence on the Italian poete Dante Aligheri, who has a character in his Divine Comedy named Matilda, who is thought to be based on her.
Here is an English translation of one of her poems:
Love flows from God into man,
Like a bird
Who rivers the air
Without moving her wings.
Thus we move in His world
One in body and soul,
Though outwardly separate in form.
As the Source strikes the note,
Humanity sings --
The Holy Spirit is our harpist,
And all strings
Which are touched in Love