In Cool Runnings, Yul Brenner asks Jr. “Look in the mirror and tell me what you see?” The idea is that you live in accordance with your self-identity.
That is essentially where Kevin DeYoung goes, without the Cool Runnings reference, in the 7th chapter of The Hole in Our Holiness. He hits on our new identity in Christ, or in union with Christ. He gives us a concise version of Walter Marshall’s classic The Gospel Mystery of Sanctification. Marshall sees sanctification as the result of our union with Christ.
In a sense, this goes into what the gospel produces. Our union with Christ is why we are justified, sanctified and empowered by the Spirit. But I am getting ahead of myself, and DeYoung.
Our union with Christ is a much neglected doctrine. But recent releases by people like Robert Letham, J. Todd Billings and Maurice Roberts are trying to rectify this. Our union with Christ brings us all the blessings of God found in salvation (Eph. 1:3). If we are not “in Christ” we have none of these many blessings.
It is not a spatial thing. We are not physically joined to Jesus, as if we are chained together, super glued together or some such thing. DeYoung notes three things our union with Christ implies: solidarity, transformation and communion. Covenant Theology understands that all are born “in Adam”, in covenant solidarity under his headship. As a result, we are fallen, guilty and sinning. The new covenant gives us a new head. We are in covenant solidarity in Christ so that His obedience is ours (Romans 5).