"I am stunned that you are so quickly abandoning the one who called you by the Grace of Christ and turning to a different gospel — not that there actually is another one. But certain people are confusing you and trying to twist the Gospel of Christ into something it's not.
Let me be absolutely clear: even if we ourselves — or an angel from heaven — preached a gospel to you that contradicts what we originally told you, let that person be cursed. I said it before, and I'll say it again: if anyone is preaching to you a gospel different from the one you already received, let them be cursed.
Does that sound like I'm trying to win popularity points? Am I seeking human approval — or God's? If I were still trying to make people happy, I wouldn't be a servant of Christ."