“…it is not only in being ‘united to him in his circumcision-death’ but also, especially in being united to him in his resurrection that “everything that happened to him” happens to us in our past, is happening, and will happen to us. Some passages will focus on believers’ union with an attribute of Christ whereby the believer is seen to be represented by Christ in such a way that the believer is fully identified with that attribute of Christ; in other words, what Christ is, the believer (in union with Christ) is. For example, we will see that in the case of the classic doctrine of justification (declaration of believers’ righteousness), when believers come into union with the resurrected Christ, they are credited with his perfect righteousness; that is, they are represented by the perfectly righteous, ascended Christ and are considered and seen to be perfectly righteous...
…union with Christ entails a vital, living relationship with Christ, which some may call “mystical” union.” “It is nothing less than a life-union, a union in life shared with Christ… a union in life with Christ [which] is also Spiritual,” because it is effected by the enlivening work of the Spirit in the Christian.” (Union with the Resurrected Christ, pgs. 4-5, 7)