Is it okay for a Christian to sue another Christian for defamation if they lie about you publically and refuse to tell the truth?
For a individual Christian, the answer would have to be NO. Christians are to rise above the standards of the world, live in ongoing forgiveness (as Christ does for us) and not bring shame to the name of Jesus by dragging our dirty laundry out in front of the unsaved world. Consider these verses:
Proverbs 25:8-10 Go not forth hastily to strive, lest thou know not what to do in the end thereof, when thy neighbour hath put thee to shame. Debate thy cause with thy neighbour himself; and discover not a secret to another: Lest he that heareth it put thee to shame, and thine infamy turn not away. (NKJV)
1 Corinthians 6:1-11 Dare any of you, having a matter against another, go to law before the unrighteous, and not before the saints? Do you not know that the saints will judge the world? And if the world will be judged by you, are you unworthy to judge the smallest matters? Do you not know that we shall judge angels? How much more, things that pertain to this life? If then you have judgments concerning things pertaining to this life, do you appoint those who are least esteemed by the church to judge? I say this to your shame. Is it so, that there is not a wise man among you, not even one, who will be able to judge between his brethren? But brother goes to law against brother, and that before unbelievers! Now therefore, it is already an utter failure for you that you go to law against one another. Why do you not rather accept wrong? Why do you not rather let yourselves be cheated? No, you yourselves do wrong and cheat, and you do these things to your brethren! Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God. And such were some of you. But you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus and by the Spirit of our God. (NKJV)
Matthew 5:38-42 “You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ But I tell you not to resist an evil person. But whoever slaps you on your right cheek, turn the other to him also. If anyone wants to sue you and take away your tunic, let him have your cloak also. And whoever compels you to go one mile, go with him two. Give to him who asks you, and from him who wants to borrow from you do not turn away. (NKJV)
It’s a matter of principle, appearance and demonstrating by our behavior what Christ has done for us.
Which is better? For you to be wronged, BUT… the world sees you respond with love, forgiveness, mercy and patience?
Or for you to take your Christian brother to court because he “deserves” it? Legally, ethically and morally you would be correct in doing so. But would Christ receive the greater glory? And that is the real issue, not our reputation, feelings or “rights”.
For Christians, the answer is clear. We are not to sue our professing Christian brothers lest the world, whom we will judge some day, look at Christ’s Body and mock Him because His own children have to turn to “the world” to solve their disputes.