A good study of Acts 15 would probably answer a lot of questions about HRM and other "law-keeping"/legalistic groups which claim to use Scripture to "proof-text" those "added" doctrines...like Sabbath keeping/Saturday worship, keeping kosher, keeping the Feasts (Leviticus 23), baptismal regeneration, tithing, etc.:
The proof is in the Scripture
"But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command [them] to keep the law of Moses. ¶ And the apostles and elders came together for to consider of this matter."
Acts 15:5
The issue of how to treat the gentile believers is not a new question in our day, the Apostles themselves dealt with this issue on more than one occasion. Acts 15 shines ample light on not only the question, but the answer as well. As we read in Acts 15, we see the bible "heavyweights" like Paul and Barnabas called on the carpet along with the rest of the apostles to figure this out. And as with most issues in the church, the whole problem started with a small handful of troublemakers:
"And certain men which came down from Judaea taught the brethren, [and said], Except ye be circumcised after the manner of Moses, ye cannot be saved."
Acts 15:1
A few bad apples...
Now, we are not told who these troublemakers are, but it was sufficient to throw a monkeywrench into the whole deal:
"When therefore Paul and Barnabas had no small dissension and disputation with them, they determined that Paul and Barnabas, and certain other of them, should go up to Jerusalem unto the apostles and elders about this question."
Acts 15:2
And deal with it they did..."And when there had been much disputing, Peter rose up, and said unto them, Men [and] brethren, ye know how that a good while ago God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe.
Acts 15:8 And God, which knoweth the hearts, bare them witness, giving them the Holy Ghost, even as [he did] unto us;
Acts 15:9 And put no difference between us and them, purifying their hearts by faith."
Acts 15:7-9
They acknowledged that while a gentile does not become a Jew when believing on the Messiah, the line of division between them no longer exists. From God's perspective then, there is no difference between a Jewish and Gentile believer in Christ. But they didn't stop there, they continued on to answer this question in a most resolute and final way.
The Apostles settle this question once and for all
"Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear? But we believe that through the grace of the Lord Jesus Christ we shall be saved, even as they. Then all the multitude kept silence, and gave audience to Barnabas and Paul, declaring what miracles and wonders God had wrought among the Gentiles by them."
Acts 15:10-12
Peter is so bold that he stuns them all into silence, and uses this time to allow Paul and Barnabas to recount all the awesome 'miracles and wonders that God had wrought among the Gentiles by them'. Just when you think it can't get any more intense that it already is, James steps in begins to wrap it up:
"And after they had held their peace, James answered, saying, Men [and] brethren, hearken unto me: Simeon hath declared how God at the first did visit the Gentiles, to take out of them a people for his name. And to this agree the words of the prophets; as it is written, After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up: That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is called, saith the Lord, who doeth all these things. Known unto God are all his works from the beginning of the world. "
Acts 15:13-18
The Hebrew Roots Cult Movement - Part 1: Origins and Beliefs
Here are the four things which were required of the Gentiles (only 4...not 613):
Acts 15:19 Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God:
Acts 15:20 But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.