Us Calvinist-types are occasionally criticized for being overly morose and off-putting with our harping on such doctrines as total depravity. I think, however, that Dr. Sibbes clues us into the spiritual benefit of remembering one's past and present sin,
It is a very hard thing to bring a dull and an evasive heart to cry with feeling for mercy. Our hearts, like criminals, until they be beaten from all evasions, never cry for the mercy of the Judge.- Richard Sibbes, The Bruised Reed.
Again, this bruising makes us set a high price upon Christ. Then the gospel becomes the gospel indeed; then the fig leaves of morality will do us no good. And it makes us more thankful, and, from thankfulness, more fruitful in our lives; for what makes many so cold and barren, but that bruising for sin never endeared God's grace to them?
Likewise this dealing of God establishes us the more in his ways, having had knocks and bruisings in our own ways... Ungodly spirits, ignorant of God's ways in bringing his children to heaven, censure broken hearted Christians as miserable persons, whereas God is doing a gracious, good work with them. It is no easy matter to bring a man from nature to grace, and from grace to glory, so unyielding and intractable are our hearts.
As Paul set the glory of saving grace against the backdrop of the Ephesians' prior exclusion from God, so must we set our own minds on the sin which is ever-present in our lives. Walking in holiness is no easy matter and takes a little bruising along the way.