Galatians 1:6-7
I marvel that ye are so soon removed from Him that called you into the grace of Christ unto another gospel:
Which is not another; but there be some that trouble you, and would pervert the gospel of Christ.
Paul was disappointed at the people of Galatia, falling for something other than the Gospel of Jesus Christ, which he had carefully laid out for them. There were false teachers infiltrating the church and false doctrines being spread, and this concerned the apostle greatly. Paul warned the believers that these people would pervert the Gospel, rendering it useless to them because it was not the true Gospel.
We see the same thing happening today. It is so sad to watch false teachers who have crowds of folks fawning over them, falling at their feet, and believing the garbage that they spew from the pulpit. They use all kinds of atrocious histrionics to make their point. They deceive the masses, and God is not pleased. Believers must stay in the Word, stay in prayer and stay close to the LORD Jesus Christ in order to have the wisdom and discernment that it takes to see through false teachers. Though false teachers are pretty brazen these days, and one would think that it doesn't take much to spot their lies, it still takes the power of the Holy Spirit to protect the believers from their deception. Believers, stay in the Word! When you know the truth, you can more easily see through the lies.