People are slaves to whatever has mastered them; Freedom is never free

2 Peter 2:10-22
But these people blaspheme in matters they do not understand. They are like unreasoning animals, creatures of instinct, born only to be caught and destroyed, and like animals, they too will perish. They will be paid back with harm for the harm they have done. Their idea of pleasure is to carouse in broad daylight. They are blots and blemishes, reveling in their pleasures while they feast with you.
These people are springs without water and mists driven by a storm. Blackest darkness is reserved for them. 
They promise them freedom, while they themselves are slaves of depravity—for “people are slaves to whatever has mastered them."
 It would have been better for them not to have known the way of righteousness than to have known it and then to turn their backs on the sacred command that was passed on to them. 
They are anti-authority. They respect no one. They teach self-gratification, and their dissolute lives deny the Lord and shame his church. They trade in false hope, promising freedom from restraint which is, in reality, another enslavement. Their punishment is certain and terrible: the rescue of God's people is equally sure. The writer takes Old Testament examples; the flood, and the rescue of Noah; the destruction of Sodom and Gomorrah, and the rescue of Lord.
Why?
Peter criticized those blaspheme men, they did not know what they are doing. They are like animals, will be caught and be killed and perish.
Those people are like springs without water, it pretends a solution, but it is the way to the dead.
The freedom os the slaves of depravity, if the slave of Jesus Christ will have real freedom, but the slave to whatever has mastered them will perish.
When we know the righteousness and the love of God should aware that don't forsake God's grace or will be worse than the beginning.
How?
Real freedom is under God's grace and salvation! Freedom is never free.