The nature of love is that it is diffusive, unifying, and transforming. It is diffusive when it flows out and sheds the rays of its goodness not merely on friends and neighbors, but on enemies and strangers as well. It unites because it makes lovers one in deed and will, and draws into one Christ and every holy soul. He who holds on to God is one in spirit with him, not by nature, but by grace and identity of will. Love has also the power of transforming, for it transforms the lover into his Beloved, and makes him dwell in him. Thus it happens that when the fire of the Holy Spirit really gets hold of the heart it sets it wholly on fire and, so to speak, turns it into flame, leading it into that state in which it is most like God.
–Richard Rolle (c. 1300-1349)