What God commands us to do (the imperative) is based upon what he has done, is doing or will do (the indicatives). Example –
. . .work out your salvation with fear and trembling, for it is God who works in you to will and to act according to his good purpose.
“To say what we should be or do and not link it with a clear exposition of what God has done about our failure to be or do perfectly as he wills is to reject the grace of God and to lead people to lust after self-help and self improvement in a way that, to call a spade a spade, is godless.” Graeme Goldsworthy, “Preaching the Whole Bible as Christian Scripture”, Grand Rapids; Eerdmans 2000