You have a misunderstanding of the Catholic belief in the priesthood. Christ said to confess to one another. He also gave the apostles the ability to forgive sins. All priests descend from the line of the apostles unbroken through the centuries. Catholics believe that when a priest administers the sacraments (such as absolution in confession), he does so in the person of Christ. This means that Christ Himself literally works through the agency of the priest and is actually the one granting the absolution. The priest cannot and does not absolve sins by his own human agency.