The Galatians had difficulties in part because it was hard for them to see some of the evil in their age. There's nothing unique to their situation, however, and the same thing can easily happen to us. Even once we have identified a potential source of evil, there is still the problem of the wide and narrow gates. The wide gate is enticing through its ease and comfort, but it leads to destruction.
A hint to one component of Paul's own resilience is given in Gal 2:10.
Gal 2:9.: and when James, Cephas, and John, who seemed to be pillars, perceived the grace that had been given to me, they gave me and Barnabas the right hand of fellowship, that we should go to the Gentiles and they to the circumcised. 10. They desired only that we should remember the poor, the very thing which I also was eager to do. NKJV
The important thing here was that Paul was eager. He actually wanted to do the things that pleased God. It is always easiest to follow commands when the commandment is to do something that you wanted to do anyhow.
In Chapter 4 of Galatians, Paul gives an encouragement and motivation for the Galatians to be eager.
Galatians 4:3.: Even so we, when we were children, were in bondage under the elements of the world. 4. But when the fullness of the time had come, God sent forth His Son, born of a woman, born under the law, 5. to redeem those who were under the law, that we might receive the adoption as sons. 6. And because you are sons, God has sent forth the Spirit of His Son into your hearts, crying out, "Abba, Father!" 7. Therefore you are no longer a slave but a son, and if a son, then an heir of God through Christ. NKJV
With such great promise, we too ought to be eager to follow God and search out his Gospel. If not, we have to be careful that we are not becoming blind to the evil of the world by using sources apart from the Bible as a source of values.