Disclaimer: These are mostly the ideas of people smarter than me, I'm just spouting it back in my own words. =]
C.S. Lewis once said, "Those that hate goodness are sometimes nearer than those who know nothing at all about it and think they have it already." Sometimes it's so easy for us to rationalize and think that if we're not bad, then we're automatically good. But goodness isn't the mere abscence of evil. So, you don't break the ten commandments. Congratulations, well done, ...but to be good is so much more than simply not sinning. To be good is to be continually striving to better oneself; to be continually striving to draw closer to Christ. It's the difference between the Law of Moses and Messianic Law. It's the difference between rationalizing with your mind, and allowing your spirit to take the executive position. It's finally letting yourself say, "So, what about me?", and losing yourself in the service of others. It's learning how to be charitable towards your fellow men.
The Gospel is kind of funny in that if you simply allow charity to permeate through every aspect of your life, all the other commandments seem to fall into place. The Law of Christ appears to be so much more difficult than the Law of Moses, because the feeling proceeds the actions, and not vice versa. In the Law of Moses, you were given a strict, extensive list of commandments. They taught you right from wrong, good from evil. They taught you that God expected more from you than your natural man was sometimes willing to give. When Christ came, he added to the law, saying not only is it wrong to commit murder, but to even be angry with your brother. Not only is it wrong to commit adultery, but to even think about it. Etc., Etc. In early Protestant English translations of the Bible, the word "charity" is replaced with "love". Because that's exactly what charity is; the purest form of love we could ever have. The two greatest commandments are to love God and to love our fellow man. If we have pure love for our God, we'll naturally have pure love for our fellow man, and grow closer to those around us.
I'm not going to pretend like I'm anywhere near this point in my life, where I can say I have charity for all men. I want to, but I'm still learning (and I think I'm gettin better...) That's where the Atonement comes in. Christ is there to help pick us up when we can't go any further on our own. After you "love God with all your might, mind, and strength, then is his grace sufficient for you, that by his grace ye may be perfect in Christ." We give ourselves, and Christ gives us everything we need to be happy.
I love that the Gospel makes sense. Love it.