Galatians 1:8-10

But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let him be eternally condemned! As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let him be eternally condemned!

(v8-9, NIV)

It doesn't matter who it is, whoever preaches a different gospel should be eternally condemned. You shouldn't listen to someone who is preaching a different gospel even if they are someone respectable. So, maybe those at the church in Galatia were being swayed because of who was telling them. Maybe the person or people who were deceiving them were people who they trusted, so that's why they believed them. It's so important that he even repeats himself. It is also to keep them from preaching a different gospel and not just to keep them from being deceived.

Am I now trying to win the approval of men, or of God? Or am I trying to please men? If I were still trying to please men, I would not be a servant of Christ.

(v10, NIV)

Clearly, those deceivers are trying to win the approval of men. However, Paul puts it plain to them by asking what his own intentions are. They should have known that Paul was a servant of Christ. Maybe they did know, but were deceived into thinking that a pleaser of men is more credible than a pleaser of God. Or maybe they believed that a bringer of the truth would not be a slave. Unfortunately, the world puts a veil over many people's heads in that respect. Being a slave to someone else or submitting to another is not a respectable act. Therefore, it is hard to follow a slave when you possess worldly eyes. Let us put on new eyes, or truly open our eyes to see.