God's People are ignorant of His Word, how are they even going to recognize when these 'false brethren' try to sneak in?

 

Gal 2:6   But of these who seemed to be somewhat, (whatsoever they were, it maketh no matter to me: God accepteth no man's person :) for they who seemed to be somewhat in conference added nothing to me:

     These 'false brethren' evidently really thought they were 'something'. Yea, they held a big meeting with Paul, putting themselves up on a pedestal of self-righteous authority. Paul's saying those elder Jews of the Christian Church back in Jerusalem had no new revelation to add to The Gospel he received directly from Jesus Christ.
     Those who began this idea of the Gentiles needing to be circumcised to be saved were 'certain of the sect of the Pharisees which believed'

 

Acts 15:5: But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and command them to keep the law of Moses.

 

Gal 2:7   But contrariwise, when they saw that the gospel of the uncircumcision was committed unto me, as the gospel of the circumcision was unto Peter;
8    (For He That wrought effectually in Peter to the apostleship of the circumcision, the same was mighty in me toward the Gentiles:)

     The 'gospel of uncircumcision' Paul speaks of is about the circumcision of the heart, for both male and female

 

 Romans: Read All.

 

 Christ fulfilled The Law of the blood ordinances upon the cross. Notice I said 'fulfilled' and not 'done away with'. As Christ now is our True Sabbath, and our Passover sacrificed for us, He fulfilled those portions of The Law. Thus we still are to observe Passover, not in the flesh sense, but in the spiritual sense.

 

 1 Cor.5:7: Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our Passover is sacrificed for us.

 

 We are still to observe the Sabbath also, not in the flesh sense, but in the spiritual sense of Christ being our 'Rest', as that's what the word 'Sabbath' means, 'rest, intermission'

 

Col.2: Read All

Hebrews 4: Read All.

 

Gal 2:9   And when James, Cephas, and John, who seemed to be pillars, perceived the grace that was given unto me, they gave to me and Barnabas the right hands of fellowship; that we should go unto the heathen, and they unto the circumcision.

     This word 'heathen' is 'ethnos' in the Greek, meaning 'a tribe; specially, a foreign (non-Jewish) one' (Strong's no.1484). It simply means the 'ethnic' peoples, i.e. Gentiles. As written in...

Acts 9: Read All.

 Paul was sent by Christ to preach to the Gentiles, Kings, and to Israel. Others of the Apostles of Christ, such as James, would stay on in Jerusalem preaching to the 'circumcision', i.e. the Jews.