In Jude's time, he went out of his way to warn, earnestly, that the grace of God was becoming a distorted justification for sin, rather than justification, which frees us from sin!
"5I will therefore put you in remembrance, though ye once knew this, how that the Lord, having saved the people out of the land of Egypt, afterward destroyed them that believed not." (Jude 5)
Five is the number of grace, and yet in that verse Jude describes the ancient Israelites who did not receive, did not rest in this grace. Because they did not believe in the Lord, did not draw all their strength from Him, but sought to rely on themselves, they perished in the wilderness.
There is no life, there is no hope, without the grace of God:
"16For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God." (John 3: 16-18)
If we do not believe on Him, we are condemned already, and there is no way out!
Yet with the gift of righteousness comes life, His life, and thus we are led by His Spirit, not by our flesh:
"But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter." (Romans 7: 6)
When the grace of God is preached, we must contend for the truth, that grace is no a license to sin, but the freedom which gives us power over sin. Anyone who says or does otherwise is an anti-Christ. Of course, Paul could not have put it better:
"And not rather, (as we be slanderously reported, and as some affirm that we say,) Let us do evil, that good may come? whose damnation is just." (Romans 3: 8)
Like Jude, we must make it clear that the grace of God is all about Jesus, and it is the grace of God which teaches us to say "No!" to sin, but "Yes!" to godliness (Titus 2: 11-14)