What did Paul really mean when he called marriage a “great mystery” concerning Christ and the Church? In this study, we return to Genesis and follow a remarkable biblical thread through Adam and Eve, the breath of life, Ezekiel’s valley of dry bones, Christ breathing upon His disciples, and the outpouring of the Holy Spirit at Pentecost. We examine the Hebrew ish and ishshah, the meaning of ezer kenegdo, Paul’s use of kephalē (“head”), and the often-overlooked context of mutual submission in Ephesians 5. Rather than presenting woman as a lesser creation or marriage as a hierarchy of domination, Scripture reveals something far more profound: two becoming one without losing their distinction. From the first Adam to Christ, the Last Adam, the imagery of body, breath, Spirit, life, and union points toward the mystery Paul finally declares: “This is a great mystery: but I speak concerning Christ and the church.”