I’m not sure why you have a problem with the word “replace.” If you believe Paul was one of the 12, than you have to believe that he was chosen/ordained/selected to “replace” one of the original 12. Substitute the word “succeed” if you want. It means the same thing.
I didn’t like the word “replace” because when an Apostle dies his priesthood and Apostleship are not lost. He remains a priest and an Apostle forever. But he leaves a vacancy behind on earth that is filled by someone else.
I’ll tell you why I think you error in this assumption. The author of Acts obviously thought it important enough to include the story of Matthias being chosen to succeed Judas. So we can safely say that Matthias was one of the 12 Apostles. Being that Paul was a contemporary of the original 12 Apostles, you should find it odd that this same author does not make any mention of Paul succeeding one of the 12 as Matthias did.
The story of Judas and Matthias is a special case. Judas had known Jesus personally, and been directly called by Him, and then turned traitor, and died in his sin. His story was infamous enough to be told. Matthias was also a special case, partly because he filled a vacancy left by such an infamous Apostle, and partly because he was the first to fill such a vacancy, and he sets a precedent. Therefore his story needed to be told. The more relevant question that you need to ask is, Why was it necessary to fill a vacancy in the Twelve at all? Why not leave it at 11, or 9; or even call 25 Apostles so you have more people to go and preach the gospel? Why just make it up to 12? That is the real question you need to ask yourself.
Paul is selected in an entirely different manner. Though we know Paul was an apostle, neither Paul, nor Peter, nor anyone else ever calls Paul “one of the 12.” So the circumstantial evidence seems to suggest the exact opposite of what you said. It suggests that Paul was an apostle, but not one of the 12.
I agree that the circumstances of Paul’s ordination were different. Paul was not called or recruited, nor instructed by the other Apostles. His calling, as well as training and instruction came directly from the Lord Himself. He tells his own story as follows:
Galatians 1:
11 But I certify you, brethren, that the gospel which was preached of me is not after man.
12 For I
neither received it of man, neither was I taught it, but by the revelation of Jesus Christ.
15 But when it pleased God, who separated me from my mother’s womb, and called me by his grace,
16 To reveal his Son in me, that I might preach him among the heathen;
immediately I conferred not with flesh and blood:
17
Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.
18 Then
after three years I went up to Jerusalem to see Peter, and abode with him fifteen days.
His conversion, from being persecutor to becoming preacher, had been so dramatic that after the experience he did not hang around to chat with other people! He chose to go to the desert of Arabia to commune with God! And there he received his first training and instruction by revelation from the Lord. But that does not mean that he could not have been ordained to fill a vacancy in the original Twelve. The fact that the Twelve had to be kept at twelve suggests that he was. Besides Paul, how many other people do you know who were designated Apostles but were not one of the Twelve? If it didn’t make any difference how many of them there were, why not ordain 60 Apostles and send them to preach the gospel, instead of 12?
zerinus