1Eph 1:22; 2:6–8; ²1 Cor 6:17; Jn 10:28; Eph 5:23, 30; ³1 Pet 5:10; 1 Cor 1:9

The fact that there is a body known as the Church Invisible which comprises the elect of Christ, should lead us to conclude that in God’s mind, the church is beloved and united with Christ from all eternity. This is the basis of the apostle Paul’s declaration that the election and predestination of the Church is founded in Christ, or in God’s love for Christ according to a covenant bond (Eph 1:3-11).

But since we did not actually exist before the foundation of the world, this union may be regarded as potential rather than actual. Therefore, there is necessity, in the fullness of time, for this union to be realised (or ratified). This is what the apostle Paul is referring to when he says,—after detailing our elective union with Christ:

This union with Christ in time is also the subject of our current Q & A.

It is a work of God’s grace (i.e. undeserved by us), which is done at our effectual calling. We will study what is effectual calling in our next question, but for now realise that effectual calling involves a work of the Holy Spirit in our souls.

Through this work of the Spirit, we are "spiritually and mystically, yet really and inseparably, joined to Christ as their head and husband."

We are said to be "spiritually and mystically" united to Christ in that we are not materially or physically united to Him. We are the body of Christ, but only in the spiritual sense, not in the sense that Christ is actually constituted of us or that our natures are intermingled with His nature. No, we are spiritually and mystically united to Him in that His Spirit dwells in us (in a metaphorical sense which involves His claiming us to be His and working in us, not in the literal sense as if we can carry about the Holy Spirit, as some wrongly imagine). This is what Paul is saying in Roman 8:9-10—

This union, though spiritual therefore invisible, and mystical or mysterious, is not imaginary or theoretical. It is real and actual. It is a reality in the spiritual realm, which though unseen does affect our lives in many ways and must be wholeheartedly confessed by the Church. And it is also an inseparable or permanent union, for it is a union that is brought about sovereignly by Christ without any contribution on our part.

This union describes our special relationship with Christ and is painted in Scripture with several metaphors, two of which are referred to in our catechism.

Firstly, we are the body of which Christ is the head (Col 1:18; Eph 5:30). This speaks of His authority over us and also how closely we are united to Him. Thus, for example, what is done to us as a Church is said to be done to Christ (e.g. Rom 8:17; Col 1:24); and what God did for Christ becomes an assurance to us that He would do the same to us. For just as Christ rose from the dead, we are spiritually resurrected and will one day be bodily resurrected from the dead.

Secondly, Christ is spoken of as our husband. This speaks of the fact that our union with Christ is characterised by a joyous bond of love. Christ loves, protects, and provides for the Church as His beloved wife, and the Church ought to lovingly submit to Him and serve Him as her beloved husband (Eph 5:23-25). W