What does "set free from sin" mean. (Romans 6:18)

Obviously we are not immune to desire sin, as half the blokes here are coomers but still, I believe, are saved.

It doesn't appear to justify our actions, suggesting that now that we are saved that immorality, debauchery, adultery are still counted as sin. (1 Cor. 5:11). Though am open to discussion on this.

What are your thoughts?