Reconciliation between two parties consists not only in a shift in affections but also in a change in behavior. We see this throughout Scripture. For instance, James 2:14–26 says that we demonstrate that we have been put back into a right relationship with God by our good works. Our new obedience to the Lord does not secure salvation and reconciliation with Him, but it demonstrates that it has taken place. Similarly, Jesus tells us in John 14:15 that if we love Him, we will keep His commandments. By the Holy Spirit, we are given a true love for Jesus when we are reconciled to God through Him, and this affection bears fruit in obedience to the commands of Christ.
In 2 Corinthians 6:11–13, Paul capped his lengthy defense of his Apostleship with an emotional appeal for the Corinthians to complete their reconciliation with him. He called for them to return his love as one of the fruits of their reconciliation with God in Christ (see 5:20). Yet, this reconciliation would need to be reflected as well in a proper Christian ethic. We see this in today’s passage, where Paul exhorts the Corinthians not to be “unequally yoked with unbelievers” (6:14).
The Apostle calls for separating from unbelievers. For the Corinthians, this meant a separation from the false apostles who were calling Paul’s ministry into question. It was an exhortation to reject the teaching of those who promoted rank error. However, the language about temples and idols in 6:16 makes it likely that Paul was also telling the Corinthians to make a final break with worship in pagan temples and sexual immorality. Paul dealt with these issues among the Corinthian believers in an earlier letter (see 1 Cor. 6:12–20; 10:1–22), and many commentators believe such problems were still ongoing when the Apostle wrote 2 Corinthians. The Corinthians, then, were at a crossroads. They had to choose holiness lest they be cut off from the Lord.
Paul’s call not to be unequally yoked with unbelievers cannot mean that we have nothing whatsoever to do with unbelievers. Otherwise, we would have to withdraw entirely from society, which Scripture never commands us to do. The idea is that we should not participate in the wicked ways of unbelievers. John Calvin comments: “We should have no fellowship with [unbelievers] in their pollutions. For one sun shines upon us, we eat of the same bread, we breathe the same air, and we cannot altogether refrain from intercourse with them; but Paul speaks of the yoke of impiety, that is, of participation in works, in which Christians cannot lawfully have fellowship.”