It's simple. Our purpose is to follow God through life and faith. And to remember our purpose when we are faced with a decision or choice in life, we have a simple motto: "Let God Lead."
Christ calls us to follow in His steps. An overused slogan, "What Would Jesus Do?" is actually a very simple and useful question to use in finding God's will for our lives. In Luke 9:23, Jesus says, "If anyone desires to come after Me, let him deny himself, and take up his cross daily and follow Me." Psalms says, "For You are my rock and my fortress; therefore, for Your name's sake, lead me and guide me."
There are a lot of directions you can go in life, but none deliver the joy and peace that comes from living a life led by God.