From the introduction of George Hunsinger’s book, Disruptive Grace: Studies in the Theology of Karl Barth, p. 16-17.

Grace that is not disruptive is not grace […] Grace, strictly speaking, does not mean continuity but radical discontinuity, not reform but revolution, not violence but nonviolence, not the perfecting of virtues but the forgiveness of sins, not improvement but resurrection from the dead. It means repentance, judgment, and death as the portal to life. It means negation and the negation of the negation. The grace of God really comes to lost sinners, but in coming it disrupts them to the core. It slays to make alive and sets the captive free. Grace may of course work silently and secretly like a germinating seed as well as like a bolt from the blue. It is always wholly as incalculable as it is reliable, unmerited, and full of blessing. Yet it is necessarily as unsettling as it is comforting. It does not finally teach of its own sufficiency without appointing a thorn in the flesh.

Grace is disruptive because God does not compromise with sin, nor ignore it, nor call it good. On the contrary, God removes it by submitting to the cross to show that love is stronger than death. Those whom God loves may be drawn to God through their suffering and be privileged to share in his sufferings in the world, because grace in its radical disruption surpasses all that we imagine or think.