The seven sacraments · Question 4.4
“I'll only sin again, so what is the point of confessing and doing penance?”

Penance and Reconciliation — a new start in forgiveness and reconciliation
The Church's answer: Confession is not a sacrament reserved for perfect people who will never fall again. It does need a genuine intention, now, to leave the sin and change — but the chance of falling again through your own weakness and the sincerity of your repentance are not the same thing. Penance is not a fine paid for the price of forgiveness; it is a response that repairs the relationship you damaged and rehearses the new direction in concrete action.
An analogy — relearning through rehabilitation exercises
Falling again during rehabilitation does not make the treatment and the exercises a lie. What matters is refusing to explain the fall away, looking at what caused it and learning the right movement again. The analogy shows only that repentance and concrete change do not become meaningless when the same fault recurs. It does not mean God's forgiveness works like a course of physical therapy.
If they press further: “If I keep repeating the same sin, is every confession a lie?” — Not automatically. Look concretely at what drives the repetition and at the risks, and where it is needed, put counseling, treatment, a structure of accountability and an actual plan of action in place together.
In one sentence: “Confession isn't a certificate for perfect people — it's the sacrament of getting back up responsibly, without explaining the sin away, every time you fall.”