Ibsen saw guilt and shame as Protestant control mechanisms and spent much of his life criticizing them. He wrote about the two emotions almost obsessively in his literary work, and wasn't a fan of these two carriers of unhappiness. In Ghosts, guilt and shame are nasty byproducts of a world governed by shoulds. You should stick with your husband, you should love your mother, and so forth. Get rid of this garbage, says Ibsen. He's advocating for an authentic response to the world motivated by the person's heart, not by their feelings of guilt.
Pastor Manders's decades-old guilt about his attraction to Mrs. Alving fuels his ferocious protection of his reputation.
In Ghosts, feelings of guilt perpetuate a cycle of deceit.