1. We were created to be in relationship with God. Presbyterians have for centuries stated it this way in their confessions: "The chief end of man is to glorify God and enjoy Him forever." The first and most important thing to remember is that relationship always trumps action in God's economy. To know and be in His will, we must understand that our first priority is to be in relationship with Him.
2. How we do that, is by fulfilling the Great Commandment (Matthew 22:36-40). Jesus tells us in these passages that loving God and loving others are the most important commandments; echoing the truth of our first point. But how do we fulfill this commandment? We love Him by coming to know Him, and that comes by knowing His Word. When we read His Word, God then reveals Himself to us, and teaches us to love Him and others.
3. Once we've understood why we were made (relationship) and what is the first priority of life (loving God and others); we're now ready for some assignments. God gives us two, the first of which is to fulfill the Great Commission (Matthew 28:19-20). Those who know God have an obligation to tell others about Him. (And contrary to public opinion, God isn't satisfied with the old "live-a-good-life-and-others-will-ask-you" philosophy. LOTS of workers in other religions live good lives!) We are commanded by Christ to give verbal testimony to His work in our lives.
4. Next, God gives us our second assignment in Genesis 1:26-31 and Genesis 2:15. Here He tells us it's the Christian's responsibility to tend His creation. This means the accountant is as important as the pastor or missionary in God's economy; and the truck driver and coal miner are as vital to God's plan as the accountant and pastor; and the stock broker is as significant to God's structure as the coal miner and accountant, and so on. Once we form this relationship with the Father (made possible exclusively through salvation found in faith in Jesus Christ), we honor Him best, express our love for Him most clearly, and serve others more faithfully, by doing the work that is set before us.
5. Finally, to put the pieces together with the humility that gives our work power and authority, we must accept that this life is about service and sacrifice, not self-ambition or service to self. Those who would teach health/wealth principles take you away from the place God wants His people. Our motto should be echoed in the words of John the Baptist, who said of Jesus: "He must become greater and I must become lesser." (John 3:30). Other passages to support this include Romans 12:1-2 and Galatians 2:20.

     We've each been granted the privilege of expressing our love for God by our service to His creation, and how we do that will be different for all of us. The Great Author has imbued the story of human history with poignancy, power and resonance by giving each of us who are willing to serve the chance to play a role in the drama.