In Acts 1:16-26 we have the account of the Apostle Peter, the other Apostles, and the rest of the 120 disciples meeting in prayer together in an upper room, and then Peter advancing the Biblical prophetic precept of replacing the twelfth (12th) apostle (v. 20; cf. Ps 109)—Judas Iscariot—whose office had become vacant after he choose 30 pieces of silver over Christ, and then hit the eject button of life to go to his own place:
"Men and brethren, this scripture must needs have been fulfilled, which the Holy Ghost by the mouth of David spake before concerning Judas, which was guide to them that took Jesus. (17) For he was numbered with us, and had obtained part of this ministry. (18) Now this man purchased a field with the reward of iniquity; and falling headlong, he burst asunder in the midst, and all his bowels gushed out. (19) And it was known unto all the dwellers at Jerusalem; insomuch as that field is called in their proper tongue, Aceldama, that is to say, The field of blood. (20) For it is written in the book of Psalms, Let his habitation be desolate, and let no man dwell therein: and his bishoprick let another take. (21) Wherefore of these men which have companied with us all the time that the Lord Jesus went in and out among us, (22) Beginning from the baptism of John, unto that same day that he was taken up from us, must one be ordained to be a witness with us of his resurrection. (23) And they appointed two, Joseph called Barsabas, who was surnamed Justus, and Matthias. (24) And they prayed, and said, Thou, Lord, which knowest the hearts of all men, shew whether of these two thou hast chosen, (25) That he may take part of this ministry and apostleship, from which Judas by transgression fell, that he might go to his own place. (26) And they gave forth their lots; and the lot fell upon Matthias; and he was numbered with the eleven apostles."
What occurred here, was it or was it not according to God’s will? Some cast doubt upon it and claim that Paul the Apostle was the 12th apostle but is this true?
A common argument could go as follows, an excerpt from correspondence with a professing Christian:
“Thanks again for the letter, I enjoy reading them. To answer your question the apostles when they choose Matthias had no spirit of God dwelling in them. (Acts Ch1) They only received the spirit in (Acts Ch2). This leads me to believe that they made this decision blind and with[out?] the help of the Holy Spirit. The verse that I look at to confirm this is in (Rev 21:14). This verse is very clear there are only 12 Apostles of the lord thus destroying many falsehoods and cults. The thing also to consider if this is true then why is Paul claiming to be an apostle of Christ? (1Cor1:1, 2 Cor1:1 Etc.) Most every letter he starts with that claim. Was his claim challenged who knows but he was an apostle born out of season (1Cor 15:8).”
The following report is a portion of my reply, slightly edited.
Thanks for your write up on why you believe Matthias was not the 12th apostle, and why you believe Paul was. Its wonderful to see you searching the Scriptures as God's Word commands. "The heart of the righteous studieth to answer" (Pr. 15:28a). I would like to however challenge you on your thoughts on this subject, and show you what God's Word says about this.
I agree that the Holy Spirit was not indwelling them, yet He was them: “And when [Jesus] had said this, he breathed on them, and saith unto them, Receive ye the Holy Ghost:” (Jn. 20:22). This occurred after Christ’s resurrection but before His ascension, so before Acts 2. Thus, although the Spirit didn’t indwell them, He was there with them. In fact, throughout all ages the Spirit of God has been with all born again believers as seen in the OT and something Jesus addresses in Jn. 14:17, “Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you.” During the OT and while Jesus was on earth and before Acts 2, the Holy Spirit dwelled "with" true regenerate believers, but once Christ was ascended and Pentecost came, He would dwell "in" them. This is one of those great and unspeakable mysteries and gifts that Paul wrote of that came with the New Covenant. What a Wonderful Saviour! So I believe that those wise men and brethren had God’s Spirit upon them as they collaboratively choose the 12th apostle and they acted perfectly in accordance to the will of God, Who actually did the choosing using a process that was approved of in Scripture.
The following is plain Biblical proof that reveals Matthias was indeed the 12th Apostle and what happened in Acts 1 was not some kind of misguided action by Peter (who is slandered with that philosophy, as he so frequently is by high minded and ungodly Gentiles), or falsehood unresolved in Scripture, but perfectly according to God's will, and that Paul was not the 12th Apostle but a special Apostle.
1. Firstly, Acts 1 states that Matthias was chosen by God, not by Peter or the others:
"And they prayed, and said, Thou, Lord, which knowest the hearts of all men, shew whether of these two thou hast chosen,” (v. 24).
It was God's choosing, He did it, not the apostles and disciples, and the use of "lots" (v. 26) was not only an acceptable Biblical practice of choosing (mentioned throughout the OT, incl., Pr. 16:33 and 18:18, “The lot causeth contentions to cease, and parteth between the mighty”), when more than one choice or option is present, whereby God revealing whom He had chosen, but the actual choosing was in fact entirely of God:
“The lot is cast into the lap; but the whole disposing thereof is of the Lord.” (Pr. 16:33).
"Disposing" is the Hebrew "mishpat" which has the idea of justice and judgment, a decision made by God according to His judgement and justice, an act of deciding a case. Though men use lots, God uses the lots to show whom or what He has chosen. That this was approved by God is evident not only by the results of the lot but also by any absence of God speaking against this choosing of the 12th apostle. Peter invokes the Lord here ("thou hast chosen"), and had it not been God's will, Peter would've been lying and God surely would've stopped the process, or at least reproved it. Either this account would not exist in Scripture or God would have stated or done something to the contrary, either in that context or at the least somewhere else in Scripture. But as we read the account, neither happened, nor is it ever mentioned anywhere else.
2. Secondly, since Paul consistently separates his apostleship from the other apostles (not even once does he ever include himself as one of the 12, and states things specific to his apostleship, such as “one born out of due time”) — which effectually eliminates him as the 12th, if this choosing was not of God, then a prophecy (Ps. 109:8) would remain unfulfilled or at the very least would have been mentioned in its fulfilment somewhere else. But outside of Acts 1, there is no mention of this prophetic fulfilment anywhere. If Paul had fulfilled that prophecy, we can rest assured he would have said so and God would have made it very clear. But that is not the case.
Paul is mentioned as an apostle in plenty of places and he was truly an apostle indeed but he was distinguished from the other apostles in Scripture. Paul was the apostle of the Gentiles (Rom. 11:13; Gal. 1:16; 2:7-8; Eph. 3:8; 1 Tim. 2:7). He always separated himself from the other 12 apostles concerning apostleship, as you will see below, and he clearly documents what his office of apostleship was in Rom. 11:13,
“For I speak to you Gentiles, inasmuch as I am the apostle of the Gentiles, I magnify mine office:”
While Paul did preach to Jews, his special calling was to be an apostle of the Gentiles and establish the first Gentile churches across the Roman Empire. The other 12 apostles were the apostles to the Jews, while Paul was the lone apostle to the Gentiles, hence the distinctive wording, “the apostle of the Gentiles . . . mine office”.
I would agree with you that “Paul received all his training from the Lord himself and not from man (Gal 1:18-24)” but that does not mean he met the requirements specific to the twelve apostles. In fact, Paul did not meet the standards and criteria set out in Ac 1:21-22, for the office of the twelve apostles of Christ as we read:
“Wherefore of these men which have companied with us all the time that the Lord Jesus went in and out among us, Beginning from the baptism of John, unto that same day that he was taken up from us, must one be ordained to be a witness with us of his resurrection.”
Very specific criteria is listed here: the born again believer had to have always been with the Lord Jesus during His ministry, from the baptism of John unto Christ's ascension and having also witnessed His resurrection, and of the one hundred and twenty people that were joined together in Acts 1 (v. 15) there were only 2 men that met that criteria (v. 23)—besides the 11 already in that office—which were Joseph Justus, and Matthias, and it was through prayer and casting of lots that God revealed whom He had chosen of these two. Paul most definitely did not meet that requirement, as he was yet very unsaved during Christ's ministry and resurrection and even while this prayer meeting was taking place. That also tells us that Paul's office of apostle is special; he did not meet the requirements for the 12th but he held a special apostolic position which eternity will reveal to us.
3. Thirdly, the passage specifically tells us that Matthias was "numbered with the eleven" (v. 26). Twelve verses are devoted to this scene. While it is true that Peter made some mistakes, the Bible plainly identifies the mistakes. The situation in Acts 1 is completely different. It is not merely Peter acting on a personal whim, it is the entire eleven acting prayerfully in one accord with the other brethren assembled together (over one hundred more). Twelve verses of Scripture are devoted to this scene and there is no hint that they are acting contrary to God's will. In fact, they are acting in perfect unison with prophecy (v. 20; Ps. 109:8), and prayerfully, “with one accord in prayer and supplication” (vv. 24-25). Did they all act out of line and outside of God’s will? Nothing indicates that. Nowhere does Scripture say that and they did have the Holy Ghost with them (Jn. 20:22). Yes they were to wait for the Holy Ghost, of Whom they would be baptized — He would indwell them (Ac. 1:4-5) which happened on the day of Pentecost (Ac. 2), after this event of choosing the 12th apostle, but that doesn’t invalidate the truth of what occurred in the upper room in choosing the 12th apostle. Although the Holy Spirit didn’t indwell them, the Spirit was still on all of them, “he dwelleth with you” (Jn. 14:17), and after His resurrection, “he breathed on them, and saith unto them, Receive ye the Holy Ghost:” (Jn. 20:22). Furthermore, the Lord Jesus Christ plainly declared, “For where two or three are gathered together in my name, there am I in the midst of them.” (Matt. 18:20).
Not only did this group not act out of God’s will, it specifically says they were with “one accord in prayer and supplication” (Ac. 1:14) just like they were on the day of Pentecost, “they were all with one accord in one place.” (Ac. 2:1). It is clear that everything which occurred in the upper room, by prayer and supplication, was perfectly according to God’s will.
4. Fourthly, while it is true that Matthias is not mentioned by name again in Scripture, it is also true that most of the apostles are not mentioned again by name. When the apostles are mentioned in general thereafter (e.g., Ac. 2:37, 42, 43; 4:33, 35, 36, 37; 5:12, 18; 11:1; 15:2, etc.), Matthias was doubtless one of them since he had been elected to that position. Matter of fact, he is specifically numbered with them in Ac. 2:14 and 1 Cor. 15:5 by the Author of Holy Writ, the Spirit of God.
5. Fifthly, Paul actually excluded himself from the 12 apostles. He referred to the other apostles as “the twelve" (1 Cor. 15:5). He obviously knew that he was not one of the twelve and that Matthias was the 12th. He specifically distinguishes himself from the twelve apostles here in 1 Cor. 15,
“And that he was seen of Cephas, then of the twelve: . . . And last of all he was seen of me also, as of one born out of due time.” (vv. 5, 8).
In very plain English and grammatically speaking, he said there was 12 and he was not of one of them, he was as one born out of due time. And this is after the 12th apostle is chosen, and then there was him at a later date.
In 2 Cor. 12:11 he again distinguishes himself from the other apostles,
“for in nothing am I behind the very chiefest apostles, though I be nothing.”
And again in Gal. 1:17, 19,
“Neither went I up to Jerusalem to them which were apostles before me; . . . But other of the apostles saw I none,”
In conclusion, I believe the evidence is overwhelming in favour of Matthias being the 12th apostle, and the process of this choosing being perfectly in line with the will of God, while no evidence exists contrariwise that Paul was the 12th, even by the very words he penned, but rather a special Apostle, one born out of due time. To believe that Paul was the 12th apostle calls into the question the veracity of Acts chapter 1. It calls into question what Peter and the other apostles and the rest of the 120 disciples did in unison with the Lord, the Lord confirming, or, rather more accurately, directing what occurred. It leads to doubting and questioning that is unBiblical and diabolical, and denies the Word of God. How? Scripture is very clear about who took the place of the 12th apostle (Judas Iscariot), as laid out in Acts 1, God Himself choosing the replacement of the bishoprick (Matthias, vv. 20, 24), which was inline with who met the requirements to be of the twelve apostles, so those who make Paul the 12th are not only teaching something contrary to Scripture, a falsehood, but are further denying the very Word of God and denying the words of Paul himself, which is God-inspired Scripture, who said he was not of the twelve.
If this is you, stop denying the Scriptures and and stop believing a lie, especially in light of the clear evidence presented and the opposing argument clearly debunked. Those who continue to believe a lie and deny the Word of God, must give careful heed to what 1 Jn 2:20-21 says of truly saved people:
“But ye have an unction from the Holy One, and ye know all things. I have not written unto you because ye know not the truth, but because ye know it, and that no lie is of the truth.”