Union and communion with Christ are realized only through Spirit-worked faith, Calvin teaches. Communion is actual, not because believers participate in the essence of Christ’s nature, but because the Spirit of Christ unites believers so intimately to Christ that they become, as it were, flesh of His flesh and bone of His bone. From God’s perspective, the Spirit is the bond between Christ and believers, whereas from our perspective, faith is the bond. These perspectives do not contradict each other, since one of the Spirit’s principal operations is to work faith in a sinner.
Only the Spirit can unite Christ in heaven with the believer on earth. Just as the Spirit united heaven and earth in the incarnation, so in regeneration He raises the elect from earth to commune with Christ in heaven and brings Christ into the hearts and lives of the elect on earth. Thus, communion with Christ is always the result of the Spirit’s work-a work that is astonishing and experiential rather than comprehensible. The Holy Spirit is the link that binds the believer to Christ, the channel through which Christ is communicated to the believer.
Faith unites the believer to Christ by means of the Word, enabling the believer to receive Christ as He is clothed in the gospel and graciously offered by the Father. Consequently, Calvin says, “We ought not to separate Christ from ourselves or ourselves from him,” but participate in Christ by faith, for this “revives us from death to make us a new creature.”
By faith, the believer possesses Christ and grows in Him. What’s more, the degree of his faith exercised through the Word determines his degree of communion with Christ. “Everything which faith should contemplate is exhibited to us in Christ,” Calvin writes. The believer who excels in piety learns to grasp Christ so firmly by faith that Christ dwells within his heart, though He remains in heaven. The pious live by what they find in Christ rather than by what they find in themselves.
Adapted from Joel R. Beeke, Living for God’s Glory: An Introduction to Calvinism (Kindle Edition)