What do you think about Phil 2:12-13? It appears that there is a cooperation, don't you agree? We work, but it is God who puts in us the desire to work.
Brother in Christ
Once we are released from our bondage we are "free" to work out our salvation "with fear and trembling". But we have become "new creatures in Christ" with a desire to serve through the changing of our hearts by the Holy Spirit (albeit the level of faith in everyone varies). Just because God has mercifully changed us we always must keep in mind our place. God is not a "pal" or "buddy" but our holy and righteous Father.