Verses 10 and 11 go on to say, " For the death that He (Jesus) died, He died to sin once and for all; but the life that He lives, He lives to God. Likewise, you also, reckon yourselves to be dead indeed to sin, but alive to God in Christ Jesus our Lord."
Oh how I wish Paul were here now. We sure could use someone like him. He was not afraid to tell people that they were sinning and how they could obtain everlasting life. In today's day, if one was to tell someone they were sinning, he/she would be called 'judgmental'. However, we are called to do just that. We need to first examine ourselves. Speak the truth in love. We can bring the knowledge of sin to someone without judging them.
If you saw a blind person walking toward a cliff, wouldn't you warn them? Of course, you would not even think of how they may be offended at you screaming at them. They will be grateful that you ran up to them and grabbed their shoulder and explained that there is a giant cliff they were about to walk off of.
Of course, not every person will be grateful that you tell them the good news. "Most men will proclaim each his own goodness." (Proverbs 20:6) They will say something along the lines of ' well I'm a good person' 'I do good things.' 'I'm sure the good I've done will outweigh the bad.' They will be offended, because the Cross offends. Remember, it is not your job to get them to 'pray the prayer'. Your job is to plant the seed. To show the sinner his/her sin and the need for salvation. Leave the rest to God. Salvation is of the Lord.
If you, yourself, are not sure of what sin is, please look up 1 John 3:4 "...sin is lawlessness". Sin is transgression of the Ten Commandments (the Law). If you could not define sin without this verse, you may not be soundly saved. How can you be saved if you didn't know what you needed saving from? Pray that the Holy Spirit will guide you unto true salvation. Then live a life like you are a resident of Heaven. (Because you are...a saved person is not of this world. We are just in it for a time.)