When we are sharing the Gospel we must include the Law in our conversations. Our listeners need to see their guilt, their helplessness, their depth of sin, their opposition to God, and their only solution in Christ Jesus. They also need to know the consequences of their sin, but we will leave that for another post.
The Law and it’s Purpose
1) GUILT: “The law applies to those to whom it was given, for its purpose is to keep people from having excuses, and to show that the entire world is guilty before God.” (Romans 3:19)
2) HELPLESSNESS: “For no one can ever be made right with God by doing what the law commands. The law simply shows us how sinful we are.” (Romans 3:20)
3) ANTI-GOD: “Everyone who sins is breaking God’s law, for all sin is contrary to the law of God.” (1 John 3:4)
4) SIN-FILLED: “Well then, am I suggesting that the law of God is sinful? Of course not! In fact, it was the law that showed me my sin.”(Romans 7:7a)
5) SOLUTION: “Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.” (Galatians 3:24)
Do not make the mistake of sharing a squeaky-clean Gospel – merely 
saying that Jesus died for our sin is not enough. People need to know what sin is, accept their guilt, learn the consequences, recognize their inability to do anything about it, and acknowledge that Jesus is their only solution for their sin problem. I have seen data that shows that when we omit this information, 80% to 90% of people who received Jesus eventually reject Him and return to their sinful ways.
saying that Jesus died for our sin is not enough. People need to know what sin is, accept their guilt, learn the consequences, recognize their inability to do anything about it, and acknowledge that Jesus is their only solution for their sin problem. I have seen data that shows that when we omit this information, 80% to 90% of people who received Jesus eventually reject Him and return to their sinful ways. 
He Dwells -- The B'log in My Eye 