A better way to see our salvation is to say "work we will." (Phil. 2:13)
Our redemption by Christ's sacrifice was completed on the cross and proven by His resurrection.
If we have been graced by God with faith in His son we will believe and be saved and act accordingly, out of gratitude and obedience and reverence.
Because it is the will of God.
The will of God is that we use our own will. Then, and only then He will work in us. "By works a man is justified; and not by faith only".