Do we have to keep the commandments and laws given in the Old Testament (especially the laws of Deuteronomy)
No, we do not need to keep all of the commandments found in the Old Testament. The vast majority of the commands found in Exodus, Leviticus, Numbers, and Deuteronomy deal with what is called the sacrificial system, the LAW or first covenant. In these books God gave commands and directions about who was qualified to be a priest, how the priests should dress, how the tabernacle should be built, what kinds of animal and grain offerings were required for different kinds of sins, how the sacrificial offerings were to be offered, and so forth. But after Jesus came and died, this sacrificial system, this list of commands or the LAW was replaced.
Rules & Regulations
In Hebrews 8:1-12 God says that He is going to replace the sacrificial system which was also called the Old Covenant with a New Covenant. The New Covenant meant we could have our sins forgiven by believing in Jesus – not temporarily by sacrifices. The Old Covenant could never forgive our sins (Heb. 10:1), but Jesus’ blood – His death – can and does forgive our sins forever when one believes and depends on Jesus to forgive. Hebrews 9 tells us that Jesus’ death made this system obsolete. Jesus was the perfect sacrifice (John 1:29) which takes away our sin. Listen to Hebrews 10:16-18,
“THIS IS THE COVENANT THAT I WILL MAKE WITH THEM AFTER THOSE DAYS,” SAYS THE LORD: “I WILL PUT MY LAWS UPON THEIR HEART, AND UPON THEIR MIND I WILL WRITE THEM,” He then says, “AND THEIR SINS AND THEIR LAWLESS DEEDS I WILL REMEMBER NO MORE.” Now where there is forgiveness of these things, there is no longer any offering for sin. (NASB) Hebrews 10:16-18
However, the Ten Commandments are a different story. All of the Ten Commandments are repeated in the New Testament, except for the command to keep the Sabbath.
Notice there is no command found in the New Testament about the Sabbath. In fact, in I Cor. 16:2 we find the early church gathered for worship on the first day of the week – Sunday. So only nine of the original ten commandments apply to us today.
The only commandments we need to keep in the Old Testament are those that are repeated in the New Testament. Notice the command in Deuteronomy 6:6-7,
And these words, which I am commanding you today, shall be on your heart; and you shall teach them diligently to your sons and shall talk of them when you sit in your house and when you walk by the way and when you lie down and when you rise up. (NASB) Hebrews 10:16-18
This commandment is still true today. It was only the rules and regulations about the sacrificial system that were repealed. God’s word always applies to us unless He changes it.
The only commands among the Ten commandments that we need to keep are the ones repeated in the New Testament.