Freedom's "extremes": The same thing

Freedom in Christ does not mean doing what I want.
The Libertine (X)

Freedom in Christ does not mean adhering to some pattern.
The Legalist (Y)

Freedom in Christ is freedom from the bondage of self whether it be through its lusts (libertine) or through its religious use of law (legalism).

Righteousness is not on the world's line.

In essence the two "extremes" are really the same thing. Satisfying the self, which is finding satisfaction apart from God. Sin is independence and independence is independence no matter how you do it. Whether you invoke the name of God (as a useful tool) or not.

Christ, the righteousness of God isn't on the line and we won't find freedom on that line either. That line is bondage no matter where you go on it. You are in bondage to the self, no matter what end you find yourself at any given moment.