Works versus Effort

I like this description that I came across last night of the distinction between works and effort in the general introduction to the Renovare Spiritual Formation Bible:

"The opposite of grace is works, but not effort. 'Works' have to do with earning, and there simply is nothing any of us can do to earn God's love and acceptance. And, of course, we don't have to. God already loves us utterly and perfectly, and our complete acceptance is the free gift of God thorugh Jesus Christ our Lord. In God's amazing grace 'we live and move and have our being' (Acts 17:28). But if we ever hope to 'grow in grace,' we will find ourselves engaging in effort of the most strenuous kind. As Jesus says, we are to 'strive to enter through the narrow door' (Luke 13:24, emphasis added). And Peter urges us to 'make every effort to support [our] faith with goodness, and goodness with knowledge, and knowledge with self-control, and self-control with endurance, and endurance with godliness, and godliness with mutual affection, and mutual affection with love' (2 Peter 1:5-7, emphasis added)."