Stand fast therefore in the liberty by which Christ has made us free, and do not be entangled again with a yoke of bondage.
From what I have gathered over the years, there are two types of bondage – sin and the Law.
Christ sets an individual free from both.
Although the Galatians were probably non-Jewish, the false teachers wanted them to follow the Law.
Keeping the Law was impossible, even for the false teachers.
This would place the Galatians in bondage to the Law.
Likewise, a return to sin binds a person.
Once Christ sets you free, why would you ever want to return to bondage?
Imagine being a slave and told you are free but to continue to wear the shackles to prove you are free. It just would not make sense.
Now, does this give us liberty to sin?
Again, it does not.
It gives us the freedom not to sin and to do good.