The Catechism of the Catholic Church says: "Those who approach the sacrament of Penance obtain pardon from God's mercy for the offense committed against him, and are, at the same time, reconciled with the Church which they have wounded by their sins and which by charity, by example, and by prayer labors for their conversion."
It is called the sacrament of conversion because it makes sacramentally present Jesus' call to conversion, the first step in returning to the Father5 from whom one has strayed by sin. It is called the sacrament of Penance, since it consecrates the Christian sinner's personal and ecclesial steps of conversion, penance, and satisfaction.
It is called the sacrament of confession, since the disclosure or confession of sins to a priest is an essential element of this sacrament. In a profound sense it is also a "confession" - acknowledgment and praise - of the holiness of God and of his mercy toward sinful man.
It is called the sacrament of forgiveness, since by the priest's sacramental absolution God grants the penitent "pardon and peace".
Confession was the principal daily activity of Padre Pio. He had the ability to look within the souls of his penitents. It was not possible to lie to Padre Pio during a confession. He saw inside people’s hearts. Often, when the sinners were timid, Padre Pio listed their sins during the confession.
Padre Pio invited all believers to confess at least once a week. He said: "Even if a room is closed, it is necessary to dust it after a week."
In the sacrament of confession Padre Pio was very demanding. He couldn't bear people that went to him only out of curiosity.
A monk once told the following story: "One day Padre Pio didn't give absolution to a penitent and he told him: "If you go to confess to another priest to have gain absolution you will go to hell together with him". He meant that the sacrament of confession is profaned by people that don't want to change their lives. They are guilty in front of God.