Union with Christ

In Christ

Few phrases run through Paul's letters as often as ‘in Christ’. God "has blessed us in Christ with every spiritual blessing in the heavenly realms" (Ephesians 1:3): the blessings are not handed over apart from Christ but are found in him. Jesus pictured the bond as a vine and its branches:

I am the vine and you are the branches. The one who remains in Me, and I in him, will bear much fruit. For apart from Me you can do nothing.

John 15:5

Augustine drew out what this means for grace: "the vine supplies nourishment to the branches, takes none from them" Augustine. Scripture also speaks of head and body, husband and wife, cornerstone and building. Through baptism, Paul says, believers "have been united with Him like this in His death" (Romans 6:5); his word, sumphutos (σύμφυτος), suggests things grown together into one. So he can say, "I have been crucified with Christ, and I no longer live, but Christ lives in me" (Galatians 2:20).

This union is the Spirit's work and is spiritual, but it is not a mere figure for sympathy or agreement; it is real: "he who unites himself with the Lord is one with Him in spirit" (1 Corinthians 6:17). Yet believers do not become Christ, and their being is not mixed with his. In union with him they receive justification, adoption and sanctification, and at the last they share his resurrection glory.

What the church has said

Martin Luther taught that faith unites the soul with Christ as a bride with her bridegroom, so that Christ's righteousness becomes hers and her sins become his Luther, The Freedom of a Christian. John Calvin wrote that as long as Christ remains outside us, all that he suffered and did for our salvation is of no use to us, and that the Holy Spirit is the bond that unites us to him Calvin, Institutes 3.1.1. The Westminster Larger Catechism defines it:

The union which the elect have with Christ is the work of God's grace, whereby they are spiritually and mystically, yet really and inseparably, joined to Christ as their head and husband; which is done in their effectual calling.

Westminster Larger Catechism, Q. 66

Where the traditions differ

Every tradition confesses this union as the Spirit's gift of grace. They differ over how it is given and deepened. The Catholic and Orthodox churches teach that baptism grafts us into the body of Christ and the Eucharist deepens that communion; the Orthodox describe the path as theosis, a sharing not in God's essence but in his life and energies. Lutherans stress the word, baptism and the Lord's Supper as the means through which Christ gives himself. Reformed churches confess that the Spirit unites us to Christ through faith, and that the sacraments signify and seal that union. Churches that hold a memorial view of the Supper, many Baptists among them, see baptism and the Supper as testimonies to a union already given through faith (see sacrament). See also the lessons Zwingli, Calvin and Reformed theology and Holiness and perseverance.