"For over 2000 years..."

"Jesus has continued to call men to a special union with him to make himself known to the world through the Ordained Priesthood. The first priests who heard the words of Jesus to 'Come and follow me' were the Apostles; these in turn confirmed the call of those who would succeed them. The Sacrament of Holy Orders (Priesthood) was instituted by Jesus Himself so that his presence may continue to be felt and experienced throughout the world in the men who would say Yes to the call to Priesthood. The Ordained Priest is called to do the extraordinary; he is called to be another Christ, he is called to live in the person of Christ. A priest is ultimately one who gives his life for the service of the Church so that the Gospel of Jesus Christ may be proclaimed to all the corners of the world, in every age."

From the Vocations site of the Archdiocese of Toronto