Commenting on Paul’s call to work out our salvation with fear and trembling, Kathryn Tanner writes in God and Creation in Christian Theology: Tyranny or Empowerment? that this passage,

tells Christians that they have to do something: they must not be quietistically complacent, they must not sit on their hands, they must work, they must take responsibility for themselves. On the other hand, they must do so ‘with fear and trembling’: they should not trust in their own accomplishments since everything, including it seems their own power and activity, is given to them by God.

Quoted in Aaron Riches, “Deconstructing the Linearity of Grace,” IJST Vol 10, No 2 (2008), 185.