Question 1: Who were the apostles?
The original Greek word for apostle is apostolos meaning ‘he who is sent.’ The Bible uses this word along with the plural apostoloi which means ‘sent ones.’ This gives us an understanding of who the apostles were.
There were men chosen by Jesus, whom Jesus sent out with His message of good news. Mark 3:13-14 tells us how it happened, “And Jesus went up on the mountain and called to Him those whom He desired, and they came to Him. And He appointed twelve (whom He also named apostles) so that they might be with Him and He might send them out to preach…”
So out of the group of disciples Jesus calls to Himself on this mountain, Jesus chose twelve of them to be apostles. The picture given to us here is that all of the apostles were disciples, but not all of Jesus disciples were apostles. Mark tells us their names a few verses later: Simon whom Jesus called Peter, James, John, Andrew, Philip, Bartholomew, Matthew, Thomas, James son of Alphaeus, Thaddaeus, Simon the zealot, and Judas Iscariot.
The apostles enjoyed a special office in the early Church. There were sent by Jesus, being commissioned by Him with the authority to speak on His behalf. This of course is modeled after Jesus Himself, who is called the Chief Apostle in Hebrews 3:1. Luke 10:16 makes it clear that as Jesus was sent by His Father and spoke with the Father’s authority, so too Jesus sent his apostles out to speak with His authority. Just as anyone who rejects Jesus rejects His Father who sent Him, anyone who rejects the apostles rejects Jesus who sent them.
Most of the great European cathedrals of history and older large American churches that have stained glass usually represent the apostles as being larger than life figures, super saints, men of mythical stature. Nothing could be farther from the truth – they were common men with an uncommon calling. We learn of their common and ordinary qualities all throughout the gospels. Not understanding Jesus, not trusting Jesus, denying Jesus, scared of storms, scared of men, and lusting after power the apostles were weak and insignificant. No paparazzi would have followed them around. But after Jesus ascended back to Heaven He gives the apostles the Holy Spirit in Acts 2, and the wondrous thing about the apostles after that is that these men who used be characterized by their weakness are now characterized by their bold and fearless preaching of the gospel.
This shift in their character is even noticed in Acts 4:13 which says, “When the people saw the boldness of Peter and John, and perceived that they were uneducated, common men, they were astonished, and understood that they had been with Jesus.” Common, ordinary men who followed and proclaimed an extraordinary Savior. Their time with Jesus left an enormous mark on these men, it changed them forever.
Well, after the death of the traitor Judas, there was an opening, and the apostles choose Matthias to take his place. In choosing Matthias to replace Judas Peter gave 3 qualifications one had to meet in order to be an apostle: 1) you had to be disciple of Jesus during His earthly ministry, 2) you had to be an eyewitness of the resurrection of Jesus, and 3) you had to be called and commissioned directly by Jesus Himself. Matthias met these and was chosen.
Later in Acts 9 Jesus Himself chooses Paul to be an apostle to the Gentiles, and after this as you move onto into the New Testament you have the stunning reality that there were no more apostles called or chosen.
By the late first century this was confirmed again and again by the early Church fathers who recognized their authority was subordinate to the original apostles. This means by the standards set forth in Acts 1, there are no apostles alive today (which also means the gifts of the apostles are gone as well).
This leads to Question 2: why is the teaching of the apostles important?