As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction, 2nd Peter 3:16.
As I have mentioned before, all good theology is like a three legged stool. One leg is a verse. The next leg is a reasonable explanation of that verse, and the last and vital leg is a clear demonstration from scripture that the explanation attached to the verse was used and understood by those to whom it was ascribed.
As an example, think of Matthew 16: 17-19
Matthew 16:17 And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven.
Matthew 16:18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.
Matthew 16:19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
Those verses are central to Roman Catholic thinking. They are a starting point for teaching that Peter was the first pope and that a succession of popes would have the keys to to the kingdom of heaven. If all we had was this passage, such a theology would not be unreasonable on its face. We would have two legs of a stool. We would have a verse and we would have an explanation of that verse. Yet, if we sought for a third leg so that the stool would support us, we would come up empty.
At no time do we ever find Peter in Rome. Peter clearly gave preference to the Apostle Paul as we saw in our banner verse, 2nd Peter 3:16. When Peter erred, it wasn't made a rule in heaven, it was rebuked by the Apostle Paul, Galatians 2:11-21. In fact at no time does the Apostle Peter ever play the role given him by Roman Catholic theology. Their pet theory turns out to be a two legged stool. To sit on it requires a balancing act.
The Jehovah Witnesses use 1st Corinthians 15:50 to prove that Jesus Christ resurrected as a gas. Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption. If this was the only verse in the word of God, then their explanation of it might appear genuine. It turns out to be a pitifully unstable two legged stool. Jesus Christ himself said that he resurrected as flesh. Behold my hands and my feet, that it is I myself: handle me, and see; for a spirit hath not flesh and bones, as ye see me have, Luke 24:39.
What about the contention that The Apostles Peter and Paul preached two different gospels?
Galatians 2:6 But of these who seemed to be somewhat, (whatsoever they were, it maketh no matter to me: God accepteth no man's person:) for they who seemed to be somewhat in conference added nothing to me:
Galatians 2:7 But contrariwise, when they saw that the gospel of the uncircumcision was committed unto me, as the gospel of the circumcision was unto Peter;
Galatians 2:9 And when James, Cephas, and John, who seemed to be pillars, perceived the grace that was given unto me, they gave to me and Barnabas the right hands of fellowship; that we should go unto the heathen, and they unto the circumcision.
If you or anyone else has tried to build a three legged stool that says that from this time on, the Apostle Paul only went to the gentiles and Peter only went to the Jews, you will never find your third leg. As long as scripture records, both of the apostles, both Peter and Paul continued to minister to both Jews and gentiles. Carrying the gospel to the Jews was part of Paul's commission. But the Lord said unto him, Go thy way: for he is a chosen vessel unto me, to bear my name before the Gentiles, and kings, and the children of Israel, Acts 9:15.
Throughout the Book of Acts, the Apostle Paul always visited the Jews before he visited the gentiles, and that he did so only after the Jews in the synagogues rejected the gospel. Even after his arrest and deportation to Rome, even after the Lord came to him and assured him that he must witness in Rome, he continued to visit the Jew first and after this the gentiles. And the night following the Lord stood by him, and said, Be of good cheer, Paul: for as thou hast testified of me in Jerusalem, so must thou bear witness also at Rome, Acts 23:11.
As late as when Peter wrote 2nd Peter, he was writing to gentiles. Peter, an apostle of Jesus Christ, to the strangers scattered throughout Pontus, Galatia, Cappadocia, Asia, and Bithynia, 1st Peter 1:1. Whoever he wrote to in 1st Peter is who he wrote to in 2nd Peter. This second epistle, beloved, I now write unto you; in both which I stir up your pure minds by way of remembrance, 2nd Peter 3:1. They are the same people to whom the Apostle Paul wrote. And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you, 2nd Peter 3:15.
Trying to separate Peter and Paul's ministry in some sense that each preached different gospels to two divergent people in the sense that the two gospels were ineffective and void if preached to the wrong people, is a shaky two legged stool that will never find verification in scripture.
If you want to preach that because the Jews were learned in the Law of Moses and in that some of them had salvation prior to the death burial and resurrection of Jesus Christ, and that that made them distinctly different from the gentiles who had no such knowledge or salvation, you are in a rich field in which to preach. When Peter preached in the first few chapters of Acts, he preached to men and women who knew the laws of God. They were easily made to see their guilt and were converted by the thousands.
To preach the gospel of the circumcision differed in that the circumcision knew who the God of Israel was. They knew the penalty of sin and the severity of God. Peter brought it home to them using the sign that God gave at Pentecost, and by bringing them into condemnation by showing them who Jesus Christ was.
This is in perfect accord with Paul's gospel.
1st Timothy 1:7 Desiring to be teachers of the law; understanding neither what they say, nor whereof they affirm.
1st Timothy 1:8 But we know that the law is good, if a man use it lawfully;
1st Timothy 1:9 Knowing this, that the law is not made for a righteous man, but for the lawless and disobedient, for the ungodly and for sinners, for unholy and profane, for murderers of fathers and murderers of mothers, for manslayers,
1st Timothy 1:10 For whoremongers, for them that defile themselves with mankind, for menstealers, for liars, for perjured persons, and if there be any other thing that is contrary to sound doctrine;
1st Timothy 1:11 According to the glorious gospel of the blessed God, which was committed to my trust.
The Apostle Paul used the law of God to bring people under condemnation. Did he not convince his hearers on Mars Hill that idolatry (the second commandment) was sin?
Acts 17:29 Forasmuch then as we are the offspring of God, we ought not to think that the Godhead is like unto gold, or silver, or stone, graven by art and man's device.
Acts 17:30 And the times of this ignorance God winked at; but now commandeth all men every where to repent:
Unlike the gospel of the circumcision, the gospel of the uncircumcision needed to establish the laws of God in the hearer's minds and hearts. With the circumcision, that was already done. They still needed to see that they had broken those laws and had no protection therein. Both Peter and Paul strove to bring their hearers under the condemnation of the law that they might find repentance and be justified by Christ.
When either Jew or gentile received the Gospel of Jesus Christ, their respective spirits were made one with the spirit of Jesus Christ. But he that is joined unto the Lord is one spirit, 1st Corinthians 6:17. Jesus Christ's spirit is in his body which sits in heaven next to the Father. It is a physical body; Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God, 1st John 4:2. It is also a spiritual body; It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body, 1st Corinthians 15:44.
Whether Jew or gentile, we are all in one body in heaven which is both a physical and a spiritual body. That is a revelation given to the Apostle Paul, but it did not start when it was revealed. It began at the cross.
Ephesians 2:14 For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us;
Ephesians 2:15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
Ephesians 2:16 And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby:
There is no excuse on this earth for a believer who is a part of that heavenly body not to be a part of a local church which is his visible body on this earth. when you are in such a church, I hope that both the converted Jew and the converted gentile are welcome therein.