The threefold way, traced to Dionysius the Areopagite and systematized in the Middle Ages, describes the soul’s ascent in three stages: purification from sin and attachment, illumination of the mind by grace and virtue, and union with God in love. Later writers treated them as overlapping rather than strictly successive.
Three ways
The purgative, illuminative and unitive ways: the classic stages of the Christian mystical path.
Also: triplex via