Sinclair Ferguson reminds us that piety not marinated in the gospel will run out of gas-that imperatives minus indicatives equal impossibilities:

The first thing to remember is that we must never separate the benefits (regeneration, justification, sanctification) from the Benefactor (Jesus Christ). The Christians who are most focused on their own spirituality may give the impression of being the most spiritual … but from the New Testament's point of view, those who have almost forgotten about their own spirituality because their focus is so exclusively on their union with Jesus Christ and what He has accomplished are those who are growing and exhibiting fruitfulness. Historically speaking, whenever the piety of a particular group is focused on OUR spirituality that piety will eventually exhaust itself on its own resources. Only where our piety forgets about us and focuses on Jesus Christ will our piety nourished by the ongoing resources the Spirit brings to us from the source of all true piety, our Lord Jesus Christ.