Christians have referred to the original twelve disciples of Jesus as the twelve apostles. There have been men in today's church that have given themselves the title "Apostle". After all, the Bible tells us, "And he gave the apostles, the prophets, the evangelists, the shepherds and teachers, to equip the saints for the work of ministry, for building up the body of Christ" (Ephesians 4:11-12). So, why not proclaim you are an apostle if you feel that is your spiritual gift. If you notice 1 Corinthians 12, Romans 12, and 1 Peter 4, apostle is not in the spiritual gift category although there are the gifts of teaching and exhortation.
The question is, are there other apostles other than the original twelve disciples? The Bible indicates there were other apostles. In Acts 1, after Jesus's ascension, the Apostles needed to replace Judas Iscariot. Here is how it went down:
So one of the men who have accompanied us during all the time that the Lord Jesus went in and out among us, beginning from the baptism of John until the day when he was taken up from us—one of these men must become with us a witness to his resurrection.” And they put forward two, Joseph called Barsabbas, who was also called Justus, and Matthias. And they prayed and said, “You, Lord, who know the hearts of all, show which one of these two you have chosen to take the place in this ministry and apostleship from which Judas turned aside to go to his own place.” And they cast lots for them, and the lot fell on Matthias, and he was numbered with the eleven apostles (Acts 1:21-26).
According to the Bible, Matthias was now part of the twelve apostles. However, the Bible mentions another Apostle. In fact, it was Paul who mentioned him in his letter to the Galatian churches. As he was defending his ministry, he mentioned visiting Peter in Jerusalem for fifteen days and "saw none of the other apostles except James the Lord's brother" (Galatians 1:19). Wait a minute, James, the half-brother of Jesus along with his mother and other siblings thought Jesus was out of his mind in the gospel account's? Yes, that James.
How in the world did James and even Matthias become an Apostle? The Apostles were men who were specifically called by Christ as the case was for the original twelve in Matthew 10:1-7. We also saw this take place when Matthias was called in Acts 1 where the Apostles prayed to the Lord to see who would take Judas's place. When Paul identified himself as an apostle in Galatians, he wrote, "not from men nor through man, but through Jesus Christ and God the Father" (Galatians 1:1).
There was one other criteria when determining the calling of an apostle in the early church and that was being an eyewitnesses of the Resurrected Lord Jesus. Back to Acts 1, the apostles stated the man to replace Judas must have seen Jesus resurrected, which Matthias did. In fact 1 Corinthians 15 says that Jesus appeared to Peter first, then he appeared "to the twelve" (1 Corinthians 15:5). Judas hung himself just before Jesus was crucified so he could not have seen Jesus in all of his resurrected glory.
What about James? 1 Corinthians 15 answers that question:
Then he appeared to more than five hundred brothers at one time, most of whom are still alive, though some have fallen asleep. Then he appeared to James, then to all the apostles (1 Corinthians 15:6-7).
Jesus appeared to more than five hundred brothers in Christ and to his own brother. So James meets the qualification that he saw the Resurrected Lord Jesus just as the Apostle Paul did:
Last of all, as to one untimely born, he appeared also to me (1 Corinthians 15:8).
Were there other apostles? Yes, there were according to the pages of Scripture. Are there any apostles today? I highly doubt it. I know Jesus revealed himself in all his resurrected glory in the early days of the church including to the Apostle Paul, but I doubt he has done that today. There are not many accounts of men in the ministry who has seen Jesus. Yes, there have been books about people going to heaven and they saw Jesus, but these books have been proven false.
Why do some men in the church call themselves apostles? If you listen to their message, its the prosperity gospel. The prosperity gospel preys on those who want stuff from God and not God himself. If you go to a church where one of the preachers has the title of apostle, I would consider another church.
There apostles in the Bible and God used them mightily in the advancement of His kingdom, but there are not around anymore. Could God call up men to apostles in today's church? I am not sure but we have pastors and teachers to equip the saints for the work of ministry. We also have access to scripture in a way the early church did not.