I have a friend who has fallen into the World Mission Society Church of God which is an anti-Christian cult. I have been trying to witness to her and she had presented me with different beliefs that I’m having trouble answering in regards to the law. I was hoping you could help with a couple of questions I had.
One is I John 3:4; “sin is the transgression of the law.” I was asked which law is that. My immediate answer was the Ten Commandments to which she asked, "What about the Sabbath?"
Another is regarding the promise of the New Covenant. God said He will put His Spirit in us and write His law on our hearts and minds. Which Law is that? Is it the Ten Commandments or a different law?
Your confusion seems to be rooted in not understanding some terms in the Bible.
"The law of the LORD is perfect, restoring the soul;
The testimony of the LORD is sure, making wise the simple.
The precepts of the LORD are right, rejoicing the heart;
The commandment of the LORD is pure, enlightening the eyes.
The fear of the LORD is clean, enduring forever;
The judgments of the LORD are true; they are righteous altogether.
They are more desirable than gold, yes, than much fine gold; sweeter also than honey and the drippings of the honeycomb. Moreover, by them Your servant is warned; in keeping them there is great reward" (Psalms 19:7-11).
While each term in Psalms 19 emphasizes a different aspect, the various terms all refer to the same body of laws that were given by God. For further details, see Is the covenant different from the Law?
The Ten Commandments are the prologue to the body of laws known as the Law of Moses. It is not a separate set of laws. We refer to the entire body as the Old Testament or the Old Law because it was replaced by Christ with a new set of laws that we call the New Testament or the New Law.
"'Behold, days are coming,' declares the LORD, 'when I will make a new covenant with the house of Israel and with the house of Judah,not like the covenant which I made with their fathers in the day I took them by the hand to bring them out of the land of Egypt, My covenant which they broke, although I was a husband to them,' declares the LORD. 'But this is the covenant which I will make with the house of Israel after those days,' declares the LORD, 'I will put My law within them and on their heart I will write it; and I will be their God, and they shall be My people. They will not teach again, each man his neighbor and each man his brother, saying, 'Know the LORD,' for they will all know Me, from the least of them to the greatest of them,' declares the LORD, 'for I will forgive their iniquity, and their sin I will remember no more'" (Jeremiah 31:31-34).
Jeremiah is clearly stating that the New Law (the Law of Christ) would be written on the hearts of God's people. The reason is simple. One of the initial steps to becoming a Christian is learning the Bible. "So then faith comes by hearing, and hearing by the word of God" (Romans 10:17).
Sin occurs whenever a law of God is broken. An Israelite sinned when he broke a command of God found in the Law of Moses. A Christian sins when he breaks a command of God found in the Law of Christ.
Therefore, it is not a single law as your friend is trying to make it out to be, nor is it the Old Law as you attempted to answer by referring to the Ten Commandments. The world is currently under the New Law. See also Do the Ten Commandments apply to Christians?
I appreciate you helping to answer my question. It was especially helpful seeing that the Old Covenant is the Law. Thank you for helping me see that.