The Sacrament of Reconciliation, also called Penance and Confession, is an encounter with the mercy of Jesus that heals us from sin and the effects of sin. For a baptized Christian that has fallen away from God through mortal sin, the Sacrament of Reconciliation has the effect of restoring the life of grace and salvation back to the penitent.
The Church, through its saints, bishops and popes down through the ages, has consistently recommended to the faithful the practice of regular confession, even when there are no mortal sins to confess. Every devout confession has the effect of increasing the life of Christ in us.