Rules for living

I was recently asked by my Legal Ethics Professor to write a paper on my "Philosophy of Lawyering." I found this to be a big question and I began to ponder some other big questions like "who am I?" "what is my purpose?" "what is the air speed velocity of an unladen swallow?" (Monty Python). I started my discussion in the paper by synthesizing two rules from which all others flow. They are outlined below. I hope that they make sense to someone out there, and that perhaps they provide some help.
1) Whatever you do, do it all for the glory of God (Colossians 3:23) -- This rule is self-explanatory, although, like the second, difficult to apply.
2) Want nothing but to love and serve God and other people (Galatians 5:16-17) -- I find this one to be the most difficult and fail miserably at it every day. However, the first step in becoming more like Christ is in defining exactly what it is we need to do. If you can whittle away (with the Lord's help) a little bit more of what you want every day and replace it with what God wants for you, the result will be peace, purpose, and joy. As Christians, most of the time how we get into trouble is by sinning in order to "get" something we want. The object of our desires is usually not inherently bad, but the actions that we take in order to get that thing, objective, goal, person, etc. can be sins of the first order. The adulterous woman may just be seeking intimacy. The man who cheats on his taxes may just want to better provide for his family. The addict may just want peace. All of these goals are good things, but to want them is to allow oneself to be manipulated. I think that if we train ourselves to follow the above rules, we will be filled with a yearning to love and serve God, who in turn will give us His purpose for our lives -- the only path to fulfillment.