What does it mean to live my life for God?
First, it means to recognize that my life is not my own. My job, my family, my secret hopes, my dreams, my goals, my plans, my free time, my intellect -- in short, everything I have any influence over -- belong to God, not to me.
Second, it means to seek what God wants for my life. I must spend time immersed in His word, the instrument of His revealed truth. In the word, I must seek a mind changed from carnality, darkness, and worldliness to spirituality, light, and godliness. In the word, I must allow my mind to be transformed and renewed, utterly remade into His image. I must think as He thinks, love what He loves, and value what He values.
Third, it means to step out and obey God. Since my life is not my own and I know what God wants from me, I must respond in obedience. I do this not in my own power, but in Christ's power that quickens me. My will is involved in obedience, but success in this endeavor doesn't depend on my will. Rather, God sees my desire to follow and supplies my deficiency with His all-sufficient provision.
Finally, it means to leave things in His hands. He is the one who has redeemed me from the grave. He is the one who has revealed His perfect will for my life. He is the one who supplies the ability to follow. My job is to obey, to do as much as He calls me to do, and then to trust that He is in charge of the results.