The Holy 12 Apostles

The word “Apostle” is from the Greek verb apostello (ἀποστέλλω) “to send forth”. So “Apostle” means the one who is sent forth or dispatched somewhere.
It became common to especially call the circle of Christ’s 12 closest disciples “The Apostles”. And after the death of Judas who betrayed Christ, the 11 were called “The Apostles” and in the Acts of the Apostles with the addition of Matthias again we count the 12 Holy Apostles.
All four Evangelists highlight the appointment of Twelve Apostles: Mark 3:14-15, “He appointed twelve to be with him and to send them to herald, and to have power to heal the illnesses and to cast out demons”; and Matthew 10:1, which says “And when He had called His twelve disciples to Him, He gave them power over unclean spirits, to cast them out, and to heal all kinds of sickness and all kinds of disease..” St. Luke relates the appointment of the Twelve, adding nothing about their office. Afterward, we see in Mark 6:7-13, Matthew 10:5-15, Luke 9:1-5 that the Lord sends the Twelve to preach the kingdom and to heal, and gives them very definite instructions.
Giving the twelve the power to loose or bind sins makes the Apostles the first bishops of the Church. This power would later be passed on to all the true bishops of the Holy Church.