Sarah Cassidy is the sort of no-nonsense, capable woman you might expect to find as headmistress of a ­primary school. But Sarah doesn’t do children, and she doesn’t do husbands either.No. Sarah is 43, single and celibate — and determined to remain so. Each night she fastens a wire chain, known as a cilice, around her upper thigh . . .

. . . ‘It’s an easy way of knowing you’re doing penance,’ says Eileen, who lives in an Opus Dei centre in Ealing, West London. ‘I wear mine above my thigh. If you go swimming, you don’t want to leave a mark from where it has been.

via Why does Opus Dei member Sarah Cassidy attach a cilice to her leg every day? | Mail Online.

Yet,

“For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.”
(Ephesians 2:8–10 ESV)

Either we’re saved BY grace FOR good works, or we are saved BY works.  It cannot be both ways.  While these women are extreme examples, perhaps, the reality is that most of us try to ‘do penance.’  We try to make up for our sin by doing good things.  If those good works outweigh the sin, we seem to believe, God will accept us.

But that is not the gospel.  The gospel acknowledges we cannot do enough to make up for our sin.  It demands, not penance, but repentance.  The atoning was done by Christ, once for all.  To think my self-inflicted suffering, or my good works, somehow atones for my sin is to make light of Christ’s work on the cross.