Piper: fear and trembling in attacking personal sin

The text that broke though my inconsistency was Philippians 2:12-13.

Therefore, my beloved, as you have always obeyed, so
now, not only as in my presence but much more in my
absence, work out your own salvation with fear and
trembling, for it is God who works in you, both to will and
to work for his good pleasure.

Why should there be "fear and trembling" as I attack my sin and bring about salvation from self-pity? The reason given in the text is not a threat. It's a gift. Work to kill your sin, and will to kill your sin, and do it with fear and trembling because God Almighty—Maker of heaven and earth, Redeemer, Justifier, Sustainer, Father, Lover—is so close to you that your working and willing is his working and willing. Tremble at this breathtaking thought. God Almighty is in you. God is the one in you willing. God is the one in you working. Your "continuous, sustained, strenuous" effort is not only being carried out in the presence of the all-holy God, but is the very continuous, sustained, strenuous effort of God himself. I am not waiting for a miracle. I am acting a miracle. God is the decisive cause, but my will is the agent. And it becomes the agent in obedience to the command "work!" For in your working, God is working.

CT