The primitive Christians were accustomed to speak, in a language which was older than Christianity, of being "in the Spirit" -- as though Spirit were an ethereal atmosphere surrounding the soul, and breathed in as the body breathes in the air. Paul, too, used this expression, but he placed alongside it a parallel form of words, "in Christ" or "in Christ Jesus". Where we find these words used we are being reminded of the intimate union with Christ which makes the Christian life an eternal life lived in the midst of time. The deeper shade of meaning would often be conveyed to our minds if we translated the phrase "in communion with Christ". But, Paul's Christ mysticism is saved from the introverted individualism of many forms of mysticism by his insistence that communion with Christ is also communion with all who are Christ's.