Instituted by the Lord Jesus when He chose His twelve disciples among many of His followers, and called them Apostles. The selection was accomplished after a whole night of prayer, when the Lord Jesus went out to the mountain to pray (Luke 6: 12-13), and then sent them to preach saying, “The Kingdom of Heaven is at hand” (Matthew 10:7). The Lord said to them, “I chose you and appointed you that you should go and bear fruit, and that your fruit should remain” (John 15:16). He gave them the authority saying, “Assuredly I say to you, whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven” (Matthew 18:18). After the resurrection, the Lord, “Breathed on them and said to them: “Receive the Holy Spirit. If you forgive the sins of any, they are forgiven them. If you retain the sins of any, they are retained” (John 2:23), and to them only, He said, “Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all things that I have commanded you” (Matthew: 28:19-20). He gave the mystery of His Holy Body and Blood only to them saying, ‘Do this in remembrance of Me” (Luke 22:19).