William Perkins on Mystical Union:
The benefits which we receive by this Mystical union are manifold. For it is the ground of the conveyance of all grace. The first is, that by means hereof every Christian as he is a Christian or a man regenerate, hath his beginning and being in Christ, howsoever as he is a man he hath his being and subsisting in himself, as Paul saith, 1. Cor. 1. 30. Ye are of God in Christ. And, Eph. 5. 30. Ye are members of his body, of his flesh, and of his bones.(An exposition of the symbole or creed of the apostles, according to the tenour of the scripture, and the consent of orthodox Fathers of the Church, 1595; Works 300.)
His first job under this heading is to sort out the nature of our mystical union, i.e., the nature of the connection between the believer and Christ and its importance. We cannot benefit from Christ’s work until we are mystically united to him. This was Calvin’s point in Institutes 3.1. “Regenerate” here apparently refers to the Spirit’s work of raising to life the spiritually dead.
How (will some say) can this be? After this manner: The comparison is taken from our first parents. Eve was made of a rib taken out of Adams side, he being cast into a slumber: this being done, Adam awaked and said, This now is bone of my bone, and flesh of my flesh. Gen. 2. 23. Christ was nailed on the cross, and his most precious blood was shed, and out of it arise and spring all true Christians: that is, out of the merit of Christ’s death and passion, whereby they become new creatures.
Our mystical union with Christ is intimate. It is interesting in this section, however, that Perkins did not say, as we might have expected him to say, that the Spirit is the source of union. Of course it’s true that the Spirit raises the spiritually dead and grants them new life. Here, however, he turns to the work of Christ for us before turning to his work in us. We are new creatures because of Christ’s death.
Secondly, every one that believes in Christ by reason of this union hath an unspeakable prerogative: for hereby he is first united to Christ, and by reason thereof is also joined to the whole Trinity, the Father, the Son, and the holy Ghost, and shall have eternal fellowship with them.
Were this text being published now there would be comma after “Christ” in order to make his logic clear. We should understand Perkins to be saying, “everyone who believes in Christ, by virtue of this union, has a great benefit: union with Christ, and thus with the whole Trinity.”
In other words, when Perkins thought of the source of our spiritual life, he connected it closely to the objective work of Christ for us. When he thought of coming into possession of union with Christ, he thought of Spirit-wrought faith. We have the intimate union (and communion) with Christ, by grace alone, through faith alone.
Thirdly, sundry men, specially Papists, deride the doctrine of justification by imputed righteousness: thinking it is absurd, that a man should be just by that righteousness which is inherent in the person of Christ: as if we would say, that one man may live by the soul of another: or be learned by the learning of another. But here we may see, that it hath sufficient foundation.
The importance of the forensic, objective aspect of salvation and justification appears again. Notice how that, as soon as Perkins thinks of the application, he turns back to that which is applied. Notice too that he’s concerned that the reader understand that this is a Protestant doctrine. The ground of our acceptance with God is not our union with Christ— Bernard of Clairveaux had a strong doctrine of union with Christ but he did not have a Protestant doctrine of justification on the basis of the imputation of Christ’s (condign) merit.
Implicitly here too is his answer to the frequent criticism that the Protestants teach justification on the basis of a “legal fiction.” Perkins was saying, in effect, “Nonsense!” The ground of our justification is not fiction. It’s the only actual, real, condign merit that has ever been achieved: that of Jesus. By faith we are united to that Jesus and thus benefit by what he accomplished for us.
For there is a most near and straight union between Christ and all that believe in him: and in this union Christ with all his benefits according to the tenor of the covenant of grace, is made ours really: and therefore we may stand just before God by his righteousness; it being indeed his, because it is in him as in a subject; yet so, as it is also ours; because it is given unto us of God.
The medieval and Tridentine Roman church taught (falsely) that we are accepted by God on the basis of the Spirit’s work in us and our cooperation with that grace. The ground of our acceptance with God was said to be “inherent righteousness” (iustitia inhaerens) or sometimes “charity poured forth into our hearts.” This is what some Romanist apologists are now calling the “Agape” model, as if exchanging the Latin “caritas” (charity) for the Greek Agape makes a substantial difference.
In contrast to the Romish doctrine, Perkins wanted to be clear that, relative to acceptance with God, Christ’s righteousness is truly extra nos (outside us) but he himself does not remain so. Again, one hears Calvin saying: If Christ remains outside of us, he is of no benefit to us. By virtue of Sprit-wrought union with Christ, we become bone of his bone and flesh of his flesh.
On the other hand, in some contemporary accounts of mystical union it almost seems as if mystical union is everything and faith has become a mere technicality to be affirmed formally and then locked away. Having fulfilled its function faith goes away and mystical union now is said to do what for Perkins and most other Reformed writers faith was thought to do. In Perkins, however, we do not find that mystical union swallows up or replaces the forensic doctrine. Rather, Spirit-wrought faith and mystical (Spirit-wrought) union complement each other and faith plays an essential role in justification, in union, and in the Christian life that flows from our mystical union with Christ.