Answer:
This well meaning Evangelical had heard about the Catholic doctrine of indulgences, perhaps during an Evangelical sermon outlining the "errors" of the Catholic Church. Actually, the phrase above "people can pay off their sins" is quite a bit off of Catholic doctrine. Catholic doctrine has always taught that it is a sin to sell spiritual things, including indulgences, despite some wrong actions by priests 500 years ago. This article introduces stuff like Penance, Punishment, Suffering, Confession, Reconciliation and of course