How do we know if something is referring to the Mosaic law, ceremonial law, civil law, or moral law?

TL;DR:

The Mosaic Law was given as a unified covenant to Israel and was never intended to be divided into moral, ceremonial, and civil categories. Christians aren’t under Moses but under Christ, obeying by reflecting God’s unchanging character through the law of love.

what does the bible say?

Dividing the Old Testament Law into three groups is a later theological explanation of the Christian’s relationship to the Mosaic Law. While well-intentioned, it is not a biblical explanation of the Law. Moses did not segregate the Law into separate categories, nor did the New Testament authors, who taught that trying to obey part required obeying it in full (James 2:10; Galatians 5:3). Dividing it is difficult because it wasn’t intended to be divided.

The Law was given to a specific people under a specific covenant (Exodus 19:3–6; Deuteronomy 5:2–3) for a specific time in history (Galatians 3:24–25). That covenant is now obsolete (Hebrews 8:13). Christians are not under the Mosaic Law but under the law of Christ (Galatians 6:2; Matthew 5:17). Attempting to extract and enforce “moral” portions of the Mosaic Law misunderstands its place in redemptive history.

What, then, is the Christian’s connection to it? Its foundation is the character of God, as is the foundation of Christian life. God never changes, so aspects of it, such as the Ten Commandments, feel directly applicable because the same God behind them is the same today. However, Christians aren’t striving to obey the “moral” parts of the Mosaic Law but to be transformed into the character of God by the power of God (1 Peter 1:16).

from the old testament

The Mosaic Law was specifically given to the recently freed Israelite slaves. Just before the Ten Commandments are given, Exodus 20:2 reads, “I am the LORD your God, who brought you out of the land of Egypt, out of the house of slavery.” Those commandments, and the whole Law they summarize, were specifically given to Israel. This is sometimes called the Mosaic Covenant. It came through Moses or the Sinai Covenant because it was made from Mount Sinai (Exodus 19; cf. Deuteronomy 5:2–3).
The covenant and all of the laws were a single package. We read that after Moses “told the people all the words of the LORD and all the rules” (Exodus 24:3), the people responded by saying, “All the words that the LORD has spoken we will do” (Exodus 24:4). Because this was a covenant, it meant not only commands to obey but penalties if broken. See, for example, Deuteronomy 27–28.
God’s laws were based on God’s character. The Mosaic Law was given so the people of Israel would “be holy, for I the LORD your God am holy (Leviticus 19:2). Ultimately, the Law was not about obeying a collection of arbitrary laws but in living out God’s holiness within their context.

from the new testament

While Israel had broken the covenant (Hebrews 8:9; cf. Jeremiah 31:32), they continued trying to obey the Law. By Jesus’ day, many Jews viewed keeping the Law not as a reflection of God’s holiness but as a means of earning God’s favor (Luke 18:9–14).
After the church started, certain Jews began trying to force Christians to keep the Mosaic Law for the same purpose. Paul, warning that adding the Law to the gospel negated it, warned them saying, “every man who receives circumcision, that he is under obligation to keep the whole Law” (Galatians 5:3). He was saying that if someone wanted to try to add a little bit of the Mosaic Law to be righteous, then he was bound to obey the entire law perfectly to be righteous (cf. James 2:10). Therefore, the New Testament authors did not see the Mosaic Covenant as a divisible list of laws with Christians obeying some and not others. Instead, the Law was a unified whole.
The Mosaic Law was given to Israel to train them to see their need for a better law, the law of Christ (cf. Galatians 6:2). Paul commented, “the Law has become our tutor to lead us to Christ, so that we may be justified by faith. But now that faith has come, we are no longer under a tutor” (Galatians 3:24–25).
This does not mean that Christians are not to be obedient. The same reason we obey is what underlies the Law: “You shall be holy, for I am holy” (1 Peter 1:16). The Christian obeys God by striving to be righteous like He is righteous.

implications for today

How do I know what parts of the Law apply to us today? Are we supposed to obey the Ten Commandments? Many people have wondered about these things. But asking these questions kind of misses the point.

As believers, we are called to be holy like God (1 Peter 1:15–16). Just because we are saved doesn’t mean it’s okay for us to continue to sin (cf. Romans 6:1–2). We learn about God from all of Scripture, including the Old Testament and even in the Mosaic Law. However, we need to distinguish between obeying the moral principles we learn about God in the Law and literally obeying the Law itself.

Jesus was asked about the most important command in the Law, to which He answered that it is to love God and love our neighbor (Matthew 22:37–40). Every command in the Mosaic Law could be summarized as such because either it was about treating God as holy (setting aside people, animals, tools, etc.) or about loving people (making sure they didn’t fall off the roof, didn’t go hungry, etc.) So, rather than think “what commands from the Mosaic Law apply to me,” evaluate everything you do as to whether or not it is an expression of love for God and people.

For example, we do not lie because God is a God of truth and because lying harms others. We do not misuse God’s name because we love and revere Him. In both cases, we are not simply avoiding these sins because they appear in the Ten Commandments as part of Israel’s covenant law, but because those commands reflect God’s unchanging character and what true love requires. In this way, believers live under what Scripture calls the “law of Christ” (Galatians 6:2), a life shaped by love that fulfills the moral will of God revealed throughout Scripture.

understand

The Mosaic Law was given as a unified covenant to Israel and was not divided into separate moral, ceremonial, and civil categories in Scripture.
Christians are not under the Mosaic covenant but under the law of Christ.
Obedience is for all of us, based on the unchanging character of God.

reflect

Where have you felt the need to bind yourself or others to parts of the Mosaic Law as though they were still required?
Do I understand the difference between being under Moses and being under Christ?
In what ways are you tempted to measure your spiritual maturity by adherence to certain rules rather than by how deeply you reflect God’s character in love and holiness?

engage

How should understanding the covenantal context of the Mosaic Law affect debates about Sabbath, dietary laws, or the Ten Commandments?
What is the relationship between the law of Christ and the moral commands repeated in the New Testament?
How does living under the “law of Christ” reframe obedience—not as legal obligation, but as Spirit-empowered love rooted in God’s unchanging character?