We are asked two things in life. "Love God" and "Love Your Neighbor". These were the Greatest Commandments by the central figure in the world's largest religion. We didn't need to interpret if these were the most important rules. He said these were the Greatest Commandments. Everything else in morality, culture, belief, faith, and action should roll up to this. If you are a Christian, everything should be evaluated through these two imperatives. If they are, in fact, the Greatest Commandments, we should see them carved into stone in every church in the country. And onto monuments in courthouse lawns throughout the Bible belt.
But we don't.
It turns out that loving your neighbor is much more difficult than "Do Not Murder". It requires action rather than the inaction of the 10 Commandments. It is easy to finish your day and say "I didn't steal, or murder, or worship idols today" and continue your life believing that you love God and follow his commandments. The most important commandments to Christians are to love. This is so much harder, because there is no point where you have fulfilled the action completely. There is always more love to give, more neighbors that need love. We can never be satisfied that we have completed everything that is required of us. That was never the point anyway. It is an ongoing lifestyle. An outlook on life.