There is a real question in the minds of many Christians about the ethics of litigation in their life. Since Christians are supposed to follow the teachings of Jesus Christ as laid out in the Bible, most want to know what this Holy Book says about almost anything that they do in their lives. A lot of questions arise when it comes to Christians and filing lawsuits.
Perhaps the real question here is whether it's just for an injury victim to pursue a claim against another. Because if it were not, then the attorney, by backing the victim's claim, would be complicit in an act of injustice, which would be a sin.
The Law of Moses defines justice as giving to another what is due to him: "You shall not be partial to the poor or defer to the great, but in righteousness shall you judge your neighbor" (Lev 19:15). Another thread running through both testaments is the idea of protecting those most vulnerable (i.e. Deut 24:17-21; Jer 22:3; Matt 19:21; James 1:27, etc).
According to Page Law, litigation is about seeking “to protect victims who are harmed by the action or inaction of another person or entity.” When clients are injured through no fault of their own, they deserve, by the virtue of justice, to be compensated. This is maintained by Christ Himself, who blesses Zacchaeus and his household when he says, "If I have defrauded anyone of anything, I restore it fourfold" (Luke 19:8).
The answer to this question is not as straightforward as you might think or hope for. Obviously, different branches of Christianity can have their own unique take or spin on the issue, but for the most part, it does not seem that the Bible outright prohibits Christians from being involved in a lawsuit.
Christians are called upon to look at more than just the letter of the law when it comes to filing a lawsuit. Even if civil courts say that they have every right to file a lawsuit, Christians are called upon in the Bible to take a deeper look at the issue. We are called to be merciful, to forgive those who sin against us, even till seventy times seven times (cf. Matt 18:22). At the same time, we must remember that justice and mercy do not conflict. Just as there is no Redemption without a Fall, so there is no mercy without an injury to forgive.
Many Christians believe that solving a matter internally rather than through the courts is the more Christ-like way of handling things. Christianity Today has a piece about this issue, and in it, they say that having matters settled by a civilian court may deny some people the opportunity to come closer to God.
Christians are also asked to try to solve their disputes with as little conflict as possible. Fortunately, the justice system in the United States is set up to accommodate this. Many potential lawsuits are settled before they have to be hashed out in court. Mediation and pre-trial conferences can often eliminate the need to take things any farther.
The truth is that filing a lawsuit may not be a moral wrong at all for Christians. Even though forgiveness is mandatory, biblical forgiveness does not require us to pretend the wrong did not occur, or that it was no-big-deal. In fact, wrongs should be pursued, in compliance with Jesus’ teaching in Matthew 18:15: “If thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother.”
That being said, motives matter. If the suit is filed out of spite or vengeance, then that is certainly a problem. However, a genuine attempt to gain justice for oneself is nothing to be ashamed of. There are definitely situations in which some people have to go to the courts to solve their matters. It is why the courts exist, and there is nothing to be ashamed of in using them for this purpose.