Paul gives a similar Message also in 2 Corinthians 11, concerning the false gospel of 'another Jesus'. If you haven't read it, I suggest you find time, because it concerns the coming of antichrist, i.e. Satan, as 'a spurious Messiah' in our near future. You'll have to understand who 'beguiled' Eve in the Garden, and also Jesus' teaching of the seven signs of the end, as given in,

 

 Matthew 24:

Mark 13:

                             Read All.

Luke 21:

2 Thess 2:

 

Revelation 6, 9, 12 & 13, to pull that Message all together: Read All.

     So Paul is not only referring here to the false doctrine these particular Galatians were accepting, who were wanting to live strictly by Old Testament Law, shunning Christ, but to certain false doctrines pushed by even some of today's Christian Church organizations.
     It's important to know that Paul, before Christ struck him down on the road to Damascus, was a Pharisee given authority to bring Christians before the council of the Jews. And also, Paul was a scholar of the Old Testament, having been brought up by the greatest Hebrew Torah scholar of his day, Gamaliel (see

 

Acts 22:3 & 5:34: Read All.

 

The Old Testament 'declares' God's Mission of Salvation, even back in Abraham's time in Genesis. So Paul, well knowing God's Law and the prophets, which is all they had at that time in writing, was 'chosen' to preach The Gospel (Good News), and to write most of the New Testament. Therefore, it's important to realize that Paul was well qualified for the Mission which Christ and our Father chose for him, and could easily spot any false doctrine.
     There's still another Message concerning Paul's previous deception, and zeal for persecution of Christians. He lacked The Holy Spirit as 'Guide'. So just reading The Bible doesn't mean you'll get proper understanding. Nor will anyone with The Holy Spirit truly understand The Word without study. God's Spirit is our Guide in understanding His Word. We also have to meet the conditions set forth by GOD dealing with 'faith' in Him and His Son, and then try to become His servants by knowing and doing His Word, even though we can't be perfect in It while in the flesh.

9    As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed.

     The phrase 'If any man’ also means 'if any person' from the Greek, not only 'men' (Strong's no.1536). God has called some women to teach His Gospel too.

 

 Luke 2:36-38. Read All.

 

Gal 1:10: For do I now persuade men, or God? or do I seek to please men? for if I yet pleased men, I should not be the servant of Christ.

     Back in Isaiah 30 is an example of what many of the people wanted to hear.  They didn't want to hear The Word; they wanted 'smooth things' preached in their ears.  How is it today friends?  It appears that someone teaching God's Word today is labelled as a thought criminal by the world. They don't want to hear It. They want to hear that they're doing real good, and not sinning at all. God's Law is the 'Measuring Stick' by which we know the difference between righteousness and sin. The flesh is weak, and we are all sinners. Christ came to purify us through repenting to Him, offering