To begin this answer, I wish to state that this letter was written to Christians, very close in time to Jesus. James was Jewish before his conversion. Most scholars agree that he has writing to recent Jewish converts.
The law that is mentioned is done so in a context of James admonishing them for their internal disputes about picayune matters. The word law is the translation of the Greek, nomos. This leads to a logical conclusion that it was not one particular rule of the Torah, but the Torah in general, perhaps even the dietary laws. I do not see that civil laws were included here.
It's the same law that James was talking about in James 1:25 when he said ... "But whoso looketh into the perfect law of liberty, and continueth therein, he being not a forgetful hearer, but a doer of the work, this man shall be blessed in his deed."
He is talking about the ten commandments. This is the "law of liberty". And we will be judged by this law.
I do not agree that these statements are speaking of any of the Levitical laws. Or the dietary or ceremonial laws. In reading the NT, one sees a picture of a very restrictive and controlling religion. Simply look at Yeshua's interactions with he Pharisees. Greek thot stated that following the law did, indeed, bring liberty. As we follow GOD's law's and enter into a relationship with Him, we find that we are free. (I am the truth and the truth shall set you free."- Jesus. He also said that He had come to fulfill the law, not set it aside. Dietary laws were set aside in the revelation to Peter.)
Of over 600 laws, Jesus IDed the two most important one, love GOD and love others. No more not being able to walk a mile on the Sabbath.
Please pardon the disorganized spiel. I just awoke and found this.
The Golden Rule--love thy neighbor.
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