The Sacrament of Reconciliation is one instituted by Christ in the Gospels when He grants the authority to the Apostles to forgive and retain sins (Verse 23), as He had received from the Father. Christ also at this time passes the essence of the Priesthood, Persona Christi, placing the Apostles in relation to himself the same as He is in relation to the Father (Verse 21). Christ, in this very instant, passes on the authority to act in His place, in Persona Christi, to the Apostles and with that the authority and responsibility to perpetually pass and to protect that same authority for future generations. This passing of Apostolic Authority received from the hands of Christ is what we have come to call Apostolic Succession. A succession, a lineage of pastoral authority, descending through the generations of the Church, granted directly to the Apostles by the breath and hands of the Living God, Jesus Christ.
The Gospel according to St. John, Chapter 20, Verses 19-23
The Authorized Version (KJV):
19 Then the same day at evening, being the first day of the week, when the doors were shut where the disciples were assembled for fear of the Jews, came Jesus and stood in the midst, and saith unto them, Peace be unto you.
20 And when he had so said, he shewed unto them his hands and his side. Then were the disciples glad, when they saw the Lord.
21 Then said Jesus to them again, Peace be unto you: as my Father hath sent me, even so send I you.
22 And when he had said this, he breathed on them, and saith unto them, Receive ye the Holy Ghost:
23 whose soever sins ye remit, they are remitted unto them; and whose soever sins ye retain, they are retained.