 Classical mystics did not usually speak of a true “union with God.” The term “unio mystica” was devised in the thirteenth century, but few Christian mystics used that term before the modern era (McGinn 2001, 132; Jantzen 1995) — only in the modern study of mysticism has unio mystica received a central place (McGinn 2006, 427). When Abrahamic mystics do use the language of union, it involves a falling away of the separation between a person and God short of identity: the idea is more of “communion” with God than union. “Deification” means becoming God-like. All mystical experiences involve overcoming a sense of “self,” but usually not a sense of becoming another reality. In theisms, this is an alignment of spirits, not an ontological union of different substances that were once distinct. Christian mystics used various metaphors. Henry Suso (1295–1366) likened union with God to a drop of water falling into wine, taking on the taste and color of the wine (Suso 1953, 185); Jan van Ruysbroeck (1293–1381) described union as “iron within the fire and the fire within the iron;” Teresa of Avila (1515–1882) likened the soul that absorbs and is saturated with God to a sponge and water. (See Pike 1992, chap. 2; Mommaers 2009.) A “spiritual marriage” of the soul (the bride) and Christ (the bridegroom) is common. Bernard of Clairvaux (1090–1153) described unification as “mutuality of love.” Overall, classical Christian mystics usually treated “becoming one with God” as a loving union of wills with God’s or even a fusion of the mind with God’s (McGinn 2006, 427–429). Medieval Christian mystics generally interpreted the biblical claim that “it is no longer I who lives but Christ who lives in me” (Galatians 2:20) to mean the Holy Spirit was filling their mind or spirit resulting in a complete alignment of one’s will with God’s. In Sufism, when one’s sense of self passes away (fana), one is filled with the presence of Allah (baqa), although the orthodox Sufis insist that the soul does not cease to exist but only that one is unaware of it in the blinding light of the presence of Allah (Schimmel 1975).