Many are great at questioning biblical teaching and the authority of God today. They will exploit you with deceptive words. They are in the business of buying and selling through exploitation. They have made merchandise of lost souls. He encourages not live in the flesh for the lusts of men, but for the will of God.
False teachers live to gratify the natural man.
They despise authority. Sin refuses to submit to God or anyone else. Despising to live under the authority of God and the Lordship of Christ is the hallmark for false teachers. They prefer to establish final authority themselves. Peter says they are self-willed because they seek to please themselves.