God is the one committed and dedicated to me. He who began His work in me will perform it until the day of Jesus Christ's return (Philippians 1:6). Will I finish His work for Him? It is God who works in me to desire and to act according to His good purpose (Philippians 2:13). If I try to commit or dedicate myself to doing good for God I put myself under law like obligation, I try to live by external obligations or expectations rather than trusting God to live through me and guide me.
The idea that "God wants all of our life" is short sighted. Jesus Christ is our life as Colossians 3:3 states. We were dead in sin before He gave us life through new birth. God already has all of our life. God is our life!* (*Note that this is a rejoiceful tone not an angry tone).
We think that we need to live for God but the truth is that we need God to live for us. We need to trust the indwelling God to live through us. We can do nothing apart from Him and Jesus lived this example. He said that He could do nothing without the Father.