Question: "What is the difference between the ceremonial law, the moral law, and the judicial law in the Old Testament?"
Answer: The law of God given to Moses is a comprehensive set of guidelines to ensure that the Israelites' behavior reflected their status as God's chosen people. It encompasses moral behavior, their position as a godly example to other nations, and systematic procedures for acknowledging God's holiness and mankind's sinfulness. In an attempt to better understand the purpose of these laws, Jews and Christians categorize them. This has led to the distinction between moral law, ceremonial law, and judicial law.
The moral laws, or mishpatim, relate to justice and judgment and are often translated as "ordinances." Mishpatim are said to be based on God's holy nature. As such, the ordinances are holy, just, and unchanging. Their purpose is to promote the welfare of those who obey. The value of the laws is considered obvious by reason and common sense. The moral law encompasses regulations on justice, respect, and sexual conduct, and includes the Ten Commandments. It also includes penalties for failure to obey the ordinances. Moral law does not point people to Christ; it merely illuminates the fallen state of all mankind.
Modern Protestants are divided over the applicability of mishpatim in the church age. Some believe that Jesus' assertion that the law will remain in effect until the earth passes away (Matthew 5:18) means that believers are still bound to it. Others, however, understand that Jesus fulfilled this requirement (Matthew 5:17), and that we are instead under the law of Christ (Galatians 6:2), which is thought to be "love God and love others" (Matthew 22:36-40). Although many of the moral laws in the Old Testament give excellent examples as to how to love God and love others, and freedom from the law is not license to sin (Romans 6:15), we are not specifically bound by mishpatim.
The ceremonial laws are called hukkim or chuqqah in Hebrew, which literally means “custom of the nation”; the words are often translated as "statutes." These laws are not obvious to common sense; for example, the destruction of perfectly good animals for sacrifice and the rejection of food sources such as pork and rabbit. Instead, these statutes seem to focus the adherent's attention on God. They include instructions on regaining right standing with God (e.g., sacrifices and other ceremonies regarding "uncleanness"), remembrances of God's work in Israel (e.g., feasts and festivals), specific regulations meant to distinguish Israelites from their pagan neighbors (e.g., dietary and clothing restrictions), and signs that point to the coming Messiah (e.g., the Sabbath, circumcision, Passover, and the redemption of the first-born). Some Jews believe that the ceremonial law is not fixed. They hold that, as societies evolve, so do God's expectations of how His followers should relate to Him. This view is not indicated in the Bible.
Christians are not bound by ceremonial law. Since the church is not the nation of Israel, memorial festivals, such as the Feast of Weeks and Passover, do not apply. Galatians 3:23-25 explains that since Jesus has come, Christians are not required to sacrifice or circumcise. There is still debate in Protestant churches over the applicability of the Sabbath. Some say that its inclusion in the Ten Commandments gives it the weight of moral law. Others quote Colossians 2:16-17 and Romans 14:5 to explain that Jesus has fulfilled the Sabbath and become our Sabbath rest. As Romans 14:5 says, "Each one should be fully convinced in his own mind." The applicability of the Old Testament law in the life of a Christian has always related to its usefulness in loving God and others. If someone feels observing the Sabbath aids him in this, he is free to observe it.
The Westminster Confession adds the category of judicial or civil law. These laws were specifically given for the culture and place of the Israelites and encompass all of the moral law except the Ten Commandments. This includes everything from murder to restitution for a man gored by an ox and the responsibility of the man who dug a pit to rescue his neighbor's trapped donkey (Exodus 21:12-36). Since the Jews saw no difference between their God-ordained morality and their cultural responsibilities, this category is used by Christians far more than by Jewish scholars.
The division of the Jewish law into different categories is a human construct designed to better understand the nature of God and define which laws church-age Christians are still required to follow. Many believe the ceremonial law is not applicable, but we are bound by the Ten Commandments. All the law is useful for instruction (2 Timothy 3:16), and nothing in the Bible indicates that God intended a distinction of categories. Christians are not under the law (Romans 10:4). Jesus fulfilled the law, thus abolishing the difference between Jew and Gentile "so that in Himself He might make the two into one new man, thus establishing peace, and might reconcile them both in one body to God through the cross…" (Ephesians 2:15-16).