But here so many disciples joined the little company that it was found expedient to organize into a duly-authorized religious body. The hermitage was erected into a community of canons regular on March 13, 1349, and eventually it became the motherhouse of a congregation, which bore its name of Groenendaal. Francis van Coudenberg was appointed first provost, and Blessed John Ruysbroeck prior. Hinckaert refrained from making the canonical profession lest the discipline of the house should suffer from the exemptions required by the infirmities of his old age; he dwelt, therefore, in a cell outside the cloister and there a few years later died.
This period, from his religious profession (1349) to his death (1381), was the most active and fruitful of Ruysbroeck's career. His fame as a man of God, as a sublime contemplative and a skilled director of souls, spread beyond the bounds of Flanders and Brabant to Holland, Germany, and France. All sorts and conditions of men sought his aid and counsel. His writings were eagerly caught up and rapidly multiplied, especially in the cloisters of the Netherlands and Germany; early in the fifteenth century they are to be found also in England. Among the more famous visitors to Groenendaal mention is made of Johannes Tauler, but though the German preacher certainly knew and appreciated his writings, it is not established that he ever actually saw Ruysbroeck. Gerard Groote in particular venerated him as a father and loved him as a friend. And through Groote, Ruysbroeck's influence helped to mould the spirit of the Windesheim School, which in the next generation found its most famous exponent in Thomas à Kempis.
No authentic portrait of John is known to exist; but the traditional picture represents him in the canonical habit, seated in the forest with his writing tablet on his knee, as he was in fact found one day by the brethren—rapt in ecstasy and enveloped in flames, which encircle without consuming the tree under which he is resting.
After his death, stories called him the Ecstatic Doctor or Divine Doctor, and his views formed a link between the Friends of God and the Brethren of the Common Life, the ideas which may have helped to bring about the Reformation.
Literally, Ruysbroeck wrote as the spirit moved him. He loved to wander and meditate in the solitude of the forest adjoining the cloister; he was accustomed to carry a tablet with him, and on this to jot down his thoughts as he felt inspired so to do. Late in life he was able to declare that he had never committed aught to writing save by the motion of the Holy Ghost.
In none of his treatises do we find anything like a complete or detailed account of his system; perhaps, it would be correct to say that he himself was not conscious of elaborating any system. In his dogmatic writings he explains, illustrates, and enforces traditional teachings with remarkable force and lucidity. In his ascetic works, his favourite virtues are detachment, humility and charity; he loves to dwell on such themes as flight from the world, meditation upon the Life, especially the Passion of Christ, abandonment to the Divine Will, and an intense personal love of God.
In common with most of the German mystics Ruysbroeck starts from God and comes down to man, and thence rises again to God, showing how the two are so closely united as to become one. He demonstrates inclinations towards Christian universalism in writing that "Man, having proceeded from God is destined to return, and become one with Him again." But here he is careful to protest: "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." Despite this declaration, however, and other similar saving clauses scattered over his pages, some of Ruysbroeck's expressions are certainly rather unusual and startling. The sublimity of his subject-matter was such that it could scarcely be otherwise. His devoted friend, Gerard Groote, a trained theologian, confessed to a feeling of uneasiness over certain of his phrases and passages, and begged him to change or modify them for the sake at least of the weak. Later on, Jean Gerson and then Bossuet both professed to find traces of unconscious pantheism in his works. But as an offset we may mention the enthusiastic commendations of his contemporaries, Groote, Johannes Tauler, Thomas à Kempis, John of Schoonhoven, and in subsequent times of the Franciscan Henry van Herp, the Carthusians Denis and Laurentius Surius, the Carmelite Thomas of Jesus, the Benedictine Louis de Blois, and the Jesuit Leonardus Lessius. Ernest Hello and especially Maurice Maeterlinck have done much to make his writings known.
Ruysbroeck insisted that the soul finds God in its own depths, and noted three stages of progress in what he called the spiritual ladder of Christian attainment: (1) the active life, (2) the inward life, (3) the contemplative life. He did not teach the fusion of the self in God, but held that at the summit of the ascent the soul still preserves its identity. His works, of which the most important were De vera contemplatione and De septem gradibus amoris, were published in 1848 at Hanover; also Reflections from the Mirror of a Mystic (1906) and Die Zierde der geistlichen Hochzeit (1901).