The body of Christ
Paul regarded his converts not only as individuals who had been freed from sin but also as organic members of the collective body of Christ. The idea of the body of Christ probably also explains why, in his view, it is difficult to sin so badly as to lose one’s place in the people of God. Only the worst forms of denial of Christ can remove an organic member from the body of Christ.
The body of Christ is also important in Paul’s discussions of behaviour. A part of the body of Christ, for example, should not be joined to a prostitute (1 Corinthians 6:15). Since those who partake of the Lord’s Supper participate in the body and blood of Christ, they cannot also participate in the meat and drink at an idol’s table (1 Corinthians 10:14–22). Besides avoiding the deeds of the flesh, members of the body of Christ receive love as their greatest spiritual gift (1 Corinthians 13).
Those who are in Christ will be transformed into a spiritual body like Christ’s when he returns, but they are already being “transformed” and “renewed” (2 Corinthians 3:18; 4:16); the “life of Jesus” is already being made visible in their mortal flesh (4:11). Paul thought that membership in the body of Christ really changed people, so that they would live accordingly. He thought that his converts were dead to sin and alive to God and that conduct flowed naturally from people, varying according to who they really were. Those who are under sin naturally commit sins—“those who are in the flesh cannot please God” (Romans 8:8)—but those who are in Christ produce “the fruit of the Spirit” (Galatians 5:22; compare Philippians 1:11; Romans 8:2–11).
This absolutist ethical view—those in Christ are morally perfect; those not in Christ are extremely sinful—was not always true in practice, and Paul was often alarmed and offended when he discovered that the behaviour of his converts was not what he expected. It was in this context that he predicted suffering and even death or postmortem punishment for transgressions (1 Corinthians 11:30–32; 3:15; 5:4–5). Paul’s passionate extremism, however, was doubtless often attractive and persuasive. He made people believe that they could really change for the better, and this must often have happened.