Spirit-oneness:
Defined by each getting his sense of security and significance in God, rather than in one another. When the needs of acceptance, meaning, love, purpose, value, and worth are met in Christ, rather than sought in one's mate, spirit-oneness develops.
Soul-oneness:
Defined by the commitment to minister, rather than to manipulate. If one attempts to have significant needs met in one's mate, the method to get those needs met will be manipulation. However, if one's needs are met in Christ, that person is freed up to see his mate as a unique opportunity for ministry; and is then, and only then, free to love that mate unconditionally. Soul-oneness creates the ability to respect one another's thought processes, the ability to make decisions together productively, and the ability to be sensitive to one another's emotions and moods.
Body-oneness:
"Recreational sex" (the world's way) - physical pleasure without personal meaning
"Body oneness" (God's way) - physical pleasure with personal connectedness
Not "have sex" - animals can "have sex"
Not "make love" - tends to compartmentalize physical intimacy and reduce it to a series of mechanical actions
But rather "expressing love" - making physical intimacy the result of first experiencing spirit-oneness and soul-oneness; body-oneness then becomes the product of rather than the cause of relational intimacy.