Following the death of Judas and the Ascension, the remaining eleven Apostles decided they needed to select a twelfth to complete their number. The reason for this is that Jesus had chosen twelve to symbolize the twelve Tribes of Israel. But how could such a decision be made, and who would make it? It was Peter who finally came to a solution. He declared that the new Apostle should be one who was a disciple of Jesus during the entirety of his mission, from the Baptism to the crucifixion. This meant that there were two possible candidates: Matthias and Joseph, called Barsabas.
To decide which of the two should be selected, the other Apostles drew lots, as only God would know who possessed the faith and ability to be a true witness to the life and Resurrection of Jesus. The lot fell to Matthias, and he became the twelfth Apostle.
Matthias was present in the upper room during Pentecost and, after that, set out into the world to spread the Gospel. Where exactly Matthias traveled to is a matter of debate. Some say he preached the Gospel in Cappadocia on the coast of the Caspian Sea. Others that he preached in Colchis (modern day Georgia) where he was stoned to death. Still others say that he was stones in Jerusaelm and then beheaded.
Whichever path is the correct one, the story of Matthias should serve as an example to all of us. Clement of Alexandria says that Matthias was chosen not because of what he was but because of what Jesus foresaw he would become. Like Matthias, we all have the potential to do great things in the name of Jesus. We need only take that opportunity.