Since we who are redeemed share in our union with the Lord Jesus Christ, we also have union with one another. This union is both a great blessing and an obligation.

All true Christian are united to Jesus Christ
That union with Christ is made possible by the election of God's grace. We were once separated from God in a condition of spiritual death due to sin. Since no fallen man is able to do good in a pure and personal way, our reuniting with him must be a work of unmerited favor.

Ephesians 1 (particularly verse 4)
3 Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ,
4 just as He chose us in Him before the foundation of the world, that we should be holy and blameless before Him. In love
5 He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will,
6 to the praise of the glory of His grace, which He freely bestowed on us in the Beloved.
7 In Him we have redemption through His blood, the forgiveness of our trespasses, according to the riches of His grace,
8 which He lavished upon us. In all wisdom and insight
9 He made known to us the mystery of His will, according to His kind intention which He purposed in Him

That grace, which unites us together in Christ, applies the saving benefits of our Savior's atonement to depraved and uncaring hearts by the special work of the Holy Spirit. It is appropriated by the regenerate individual through the exercise of the faith implanted into his otherwise spiritually dead heart. (For more detail see the syllabus notes on objective and subjective soteriology.)

Since spiritual death is our separation from God, spiritual life is by definition our union with him. That union produces a partaking of the blessings and enablements of God in our lives.

Several illustrations are given in Scripture to help us understand and appreciate the benefits and nature of our union with Christ.

In John 15 Jesus compares our union together in him with the relationship of a vine and its branches. The primary lesson is that fruit can only be produced when the branch draws its life from the vine. Those which do not bear fruit show that they have no real union with the vine and are cut off from appearing to be a part of it.

There is a sense in which this is similar to the work of the visible church. As a body of Christ and as individuals we are to produce evidences that show the redeeming work of the Savior on our souls (Matthew 5:16). The church is also to exercise spiritual discipline by removing those from its number (after diligent attempts to restore them) who clearly and openly do not believe or care about the revealed principles and truths of God. If a person does not abide in Christ he shows evidence that he is not drawing life from him and is not in true union with him. Therefore he has no real spiritual union with those who do abide in Christ.

In 1 Corinthians 12:12-31 believers are represented as members of the body of Jesus Christ. In Ephesians 5:23 the church is likened to a bride married to our Lord who is the head.

These and other illustrations help us to understand the union we all have together by means of our union by grace in Christ.

Every member has duties to perform for the good of all the members.
There are general duties which obligate all believers, and special duties which are specialized in individuals for the good of the whole body of Christ.

Among our general duties are those of gathering for corporate worship and encouraging one another with an attitude of love. These ideas combine in the warning of Hebrews 10

24 and let us consider how to stimulate one another to love and good deeds,
25 not forsaking our own assembling together, as is the habit of some, but encouraging one another; and all the more, as you see the day drawing near.

As we learned in our study of Worship and the Sabbath (WCF chapter 21), loyal and faithful attendance at worship is an important Christian duty. We come as members of a local branch of the visible church to honor God in the ways he prescribes in his word. Worship ought to be the most unmovable item on our weekly calendars. Our planning for the week should include provisions to clear that one day for gathering as a spiritual family for the worship times called by the Elders. This is the most visible display to the community of the unity of believers as a body of Christ.

Our regular encouragement of one another in our spiritual maturity is another way our union is expressed visibly. We should look creatively and diligently for ways to stir our brothers and sisters in the Lord to love and good works. We do this when we gather for worship. We pray for one another with commitment and dedication. Paul prayed night and day for Timothy, as he said in 2 Timothy 1:3.

There are also special duties which are reflected in the special gifts and abilities God gives to individuals in his church.

The comparison of the church with a body in 1 Corinthians 12 is of special help to us in carrying out our duties and meeting our obligations to one another. Each Christian is a member of that body. Like the hand, or foot, each has specific responsibilities in using what God has given him. Some may have very humble and simple duties but they should not be diminished in importance. Every person is important in making the body function as it should (1 Corinthians 12:22-24). This mutual dependence upon one another provides care for the needy, support in times of suffering and a sharing of joy in all the blessings of God on each person.

Our union in Christ places great value upon our individuality while it reveals the awesome blessing of our communion as a covenant people. Every gift our Lord gives to an individual believer is for the benefit of the whole church.

Though united, we do not cease to be individuals
Our union with Jesus Christ does not unite us with his incommunicable attributes. We remain finite, temporal and changeable beings. There is no evidence that any attributes of deity are communicated to the redeemed.

We remain sinners saved by grace alone. We share only in those benefits secured for us by our Lord in his work of atonement and his continuing care for us as our Good Shepherd.

Though we were crucified with Christ, buried and raised with him, it is only by representation not by participation that we have union in these special works of redemption. Those represented by Christ add nothing from themselves to those acts except their need for salvation.

Our union together as believers does not eliminate the distinctions God has made in us as individuals. As we see in 1 Corinthians 12 and in other passages, we have differing abilities and blessings. No where are we told to forsake private ownership or individual achievement. But all we have should be used responsibly for the glory of God and the care of one another as loved family members in the church.

Sometimes Acts 2:44 is misused to promote a form of communism or socialism. This is not the correct interpretation of this passage and it does not reflect a socialistic economic or political sympathy in the early church. Clearly the mutual care they had was voluntary, not imposed by law or mandatory social order. The right of private ownership is presented as normative in the church when we consider the lie of Ananias and Sapphira in Acts 5:4. The work and social ethics seen in 2 Thessalonians 3:10-12 also show that voluntary care was the policy of the Apostolic church rather than any form of socialism.

In our responsibilities together in the church we have the assurance that we belong to Christ and share in his life and promises. We, as members of his church share in one another's burdens and joys.

It's good to examine our hearts and behaviors and ask, "How faithful are we each as members of the body of believers?" We should consider how we can be more faithful and effective in our worship, service and fellowship.