The severe sin of going to a non-Jewish court I

Rabbeinu Bachye (Shemos 21:1): Even though the sin of murder is serious, but the sins of stealing and profaning G‑d’s name (chilul Hashem) are even more severe than it. That is because a murderer is forgiven when he repents as we saw concerning Caine. However repentance doesn’t erase the sin of stealing because it is first necessary to return what was stolen. If it isn’t returned then the thief is never forgiven. Similarly with chilul HaShem – repentance doesn’t help because it is a more serious crime then kerisus or capital punishment. Our Sages (Yoma 86a) say that if a person does a sin punishable by kerisus or capital punishment and he repents that the combination of repentance and Yom Kippur initiates while suffering completes the process of atonement of the sin…However a person who has committed chilul Hashem, then repentance and Yom Kippur as well as suffering do nothing. His sin is only atoned through his death. Thus these two sins of theft and chilul Hashem are more serious than murder and both are included in the sin of going to a non‑Jewish court to adjudicate disputes. Chilul HaShem is included because it is unquestionably a profanation of G‑d’s name by giving honor to idolaters and glory to non‑Jews by using their services…. Theft is involved since by ignoring Torah laws and winning a judgment in a non-Jewish court it is complete theft. However the winner of the dispute doesn’t view himself as a thief and therefore he doesn’t return what he won. Consequently he is never forgiven.