As the Christian lives in this world, he/she possesses a true quality of peace with God (Romans 5:1). This peace with God is rooted in the fact that he/she is united with Jesus Christ. And, the peace that the Christian experiences with God should lead to an active pursuit of peace with others. Hebrews 12:14 says, “Pursue peace with all people, and holiness, without which no one will see the Lord.” Ultimately, this is a state of being united with both Jesus Christ and with one's own brethren in the Lord.
United With Christ
The Christian has been united with Jesus Christ. Prior to becoming a Christian, he/she was acting in ways that were contrary to Christ. Rather than being a friend to Jesus and following His instructions, he/she was a friend of the world and living according to his/her own selfish desires.
Consider the teachings of Romans 6:1-14. The passage begins with the question, “Shall we continue in sin that grace may abound” (vs. 1)? The answer, Paul says, is: “Certainly not!” “How shall we who died to sin live any longer in it” (vs. 2)? He continues to explain that those who are Christians have previously died to sin, been buried with Christ in baptism, and have risen to walk in newness of life (verses 3-4). Then, verses 5-6 says, “For if we have been united together in the likeness of His death, certainly we also shall be in the likeness of His resurrection, knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin.” Therefore, the Christian (having now been united with Christ) has put away sin from his/her life and has determined to live according to God's purposes.
The rest of the passage goes on to explain that the Christian does not live for sin any longer. Instead of using his/her body to fulfill the purposes of sin, the Christian has presented his/her body as an instrument of righteousness to God! Therefore, being united with Jesus Christ in baptism and being risen to walk in newness of life, the Christian's life is completely transformed from the life that he/she lived previously.
Galatians 3:26-27 further helps us understand the point at which we became united with Jesus Christ. “For you are all sons of God through faith in Christ Jesus. For as many of you as were baptized into Christ have put on Christ.” Notice that “as many of you as” were baptized into Christ have put on Christ (have been united with Jesus Christ). This union takes place at the point when an individual is baptized according to the instructions of God's word.
Then, not only is the Christian united with Jesus Christ and now lives according to a different purpose, but the Christian also gains access into wonderful spiritual blessings through this union. Ephesians 1:3 says, “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.” Every spiritual blessing is available to the one who has been united with Jesus Christ in baptism. Ephesians chapter 1 helps us to understand what some of these blessings are: The adoption as sons , the forgiveness of sins, and the inheritance of eternal life in Heaven. 2 Timothy 2:10 also says that salvation is “in Christ Jesus.”
Now that you have been united with Jesus Christ in baptism and gained access into every spiritual blessing, you must live united with Jesus Christ. This, as demonstrated by Romans 6, means that you must walk in newness of life and live according to Christ's purposes for your life. As summarized in Revelation 2:10, you must be faithful unto death in order to receive the crown of life.
United With Brethren
In being united with Jesus Christ (and being brought into fellowship with God), the Christian has also been brought into fellowship with his/her Christian brothers and sisters. 1 John 1:7 explains: “But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin.” Christians, therefore, become joint-partakers of the blessings in Jesus Christ with all others who are united with Christ.
Then, God requires that those who are His people conduct themselves in such a way so as to be united with his/her brethren. Consider the following passages that identify the degree to which God expects His people to be united.
1 Corinthians 1:10: “Now I plead with you, brethren, by the name of our Lord Jesus Christ, that you all speak the same thing, and that there be no divisions among you, but that you be perfectly joined together in the same mind and in the same judgment.”
1 Corinthians 12:25: “that there should be no schism in the body, but that the members should have the same care for one another.”
Philippians 1:27: “Only let your conduct be worthy of the gospel of Christ, so that whether I come and see you or am absent, I may hear of your affairs, that you stand fast in one spirit, with one mind striving together for the faith of the gospel.”
God's people are to be united in their practice of the faith of the gospel. However, this unity among God's people will not just happen by chance. Instead, it will take a great determined effort and focus. Paul said, “endeavoring to keep the unity of the Spirit in the bond of peace” (Ephesians 4:3). Philippians 4:2 describes a situation in the Philippian congregation in which two Christian sisters were (evidently) not living united. Therefore, Paul wrote, “I implore Euodia and I implore Syntyche to be of the same mind in the Lord.” Like these two sisters, whatever obstacles to unity exist, every Christian must be diligent to pursue unity with his/her Christian brothers and sisters.
John 17:20-23 helps understand why it is so important for Christians to be united with one another. The passage records the prayer of Jesus not long before His arrest and crucifixion. As He was praying, He expressed His desire for His people to be united – that they would all be one, like Jesus and the Father are one. This needed to be done so that others (nonbelievers) would believe in Jesus and glorify the Father! By implication, then, whenever God's people are not united, they hinder the cause of Jesus Christ.
The Christian's life is a united life – united with Jesus Christ and united with his/her Christian brethren. In fact, the Christian should be pursuing peace with all mankind. However, by living united with Jesus Christ, the Christian will be separated from the ways of the world and those who live in opposition to the gospel of Christ.