Here's a good easy read.
In Paul's letter to the Galatians we read of a problem that had developed in the Galatian churches. Some had come into these assemblies preaching another gospel and the Galatians were being led astray by their teaching.
I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed. Galatians 1:6-9
Notice that Paul makes clear that the other gospel being preached was not completely without basis. That is, it was not unscriptural. It was however, undispensational. The Jews who were coming from Jerusalem to trouble the saints in Galatia were adding elements from the Gospel of the Circumcision, to Paul's Gospel of the Uncircumcision.
And certain men which came down [to Galatia] from Judaea taught the brethren, and said, Except ye be circumcised after the manner of Moses, ye cannot be saved. Acts 15:1
In order to avoid the problem faced by the churches of Galatia, we must understand the content of the various gospel messages of Scripture.
The Gospel of the Circumcision
In Galatians 2, Paul refers to two different gospel messages, the gospel of the circumcision, and the gospel of the uncircumcision.
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 2:7
We shall first consider the content of the gospel of the circumcision.
In order to understand the gospel of the circumcision we must go back to the place where God instituted circumcision, the book of Genesis.
And God said unto Abraham, Thou shalt keep my covenant therefore, thou, and thy seed after thee in their generations. This is my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised. And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you. Genesis 17:9-11
God instituted circumcision as a sign of the covenant that He made with Abraham. The "Gospel of the Circumcision" is the good news that that covenant contained. God initially revealed this good news to Abraham in Genesis 12.
Now the LORD had said unto Abram, Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will show thee: And I will make of thee a great nation, and I will bless thee, and make thy name great; and thou shalt be a blessing: And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed. Genesis 12:1-3
The good news is repeated again in Genesis 15.
And he brought him forth abroad, and said, Look now toward heaven, and tell the stars, if thou be able to number them: and he said unto him, So shall thy seed be. And he believed in the LORD; and he counted it to him for righteousness. And he said unto him, I am the LORD that brought thee out of Ur of the Chaldees, to give thee this land to inherit it. Genesis 15:5-7
The two main elements of the Gospel of the Circumcision are a people and a land. Notice that in both passages above Abraham is promised a vast multiplied seed. Abraham was to be the father of millions of descendents. Obviously, if Abraham was to have millions of descendents, those descendents would need a place to live. This need is filled in the granting of a land to Abraham. The dimensions of this land are spelled out in scripture. (See Genesis 15:18-21) There is also a third bit of good news implied in the promise of Genesis 12. Abraham's descendents were to become a "nation". This indicates a governmental structure to rule over the promised people in the promised land. We will deal with this promise more fully later when we discuss the Gospel of the Kingdom.
Once we understand the content of the Gospel of the Circumcision, it is clear that it cannot apply to us. As Gentiles (those who are not physical descendents of Abraham, Isaac, and Jacob), we are not a part of the people and land promised to Abraham. We are specifically excluded from the Gospel of the Circumcision.
The Gospel of the Uncircumcision
In the Galatians passage quoted above Paul mentioned another gospel message, the Gospel of the Uncircumcision. Even the name would indicate to us that this gospel is very different than the Gospel of the Circumcision. Paul defined the content of this gospel later in the book of Galatians.
But God forbid that I should glory, save in the cross of our Lord Jesus Christ, by whom the world is crucified unto me, and I unto the world. For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision, but a new creature. Galatians 6:14,15
The heart of the gospel message that Paul preached is that circumcision profits nothing. (See also Galatians 5:2.) This is a marked contrast to the message of the Gospel of the Circumcision. Paul expanded upon the truth of the Gospel of the Uncircumcision in his letter to the Ephesians.
Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands; That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world: But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ. For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us; 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; And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby: Ephesians 2:11-16
Today access to God is not through a nation of circumcised Jews but through "one new man", the Church, the Body of Christ. In the Body of Christ circumcision and uncircumcision are not an issue. Jews and Gentiles are reconciled together in Christ, and in Him, reconciled to God.
As uncircumcised Gentiles, we can rejoice in the fact that today God is offering a gospel that includes us. No longer are we on the wrong side of the "middle wall of partition". We can now take our place, in Christ, as a part of the "household of God" (See Ephesians 2:19). This is the message of the Gospel of the Uncircumcision.
The Gospel of the Kingdom
The next gospel message that we will consider, the Gospel of the Kingdom, is closely related to the Gospel of the Circumcision that we discussed above. It is the gospel message that Christ proclaimed during His earthly ministry.
And Jesus went about all Galilee, teaching in their synagogues, and preaching the gospel of the kingdom, and healing all manner of sickness and all manner of disease among the people. Matthew 4:23
The most evident content of the Gospel of the Kingdom was that the Kingdom of Heaven was as hand. This is the message proclaimed by both Christ and His twelve apostles.
From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand. Matthew 4:17
These twelve Jesus sent forth, and commanded them, saying, Go not into the way of the Gentiles, and into any city of the Samaritans enter ye not: But go rather to the lost sheep of the house of Israel. And as ye go, preach, saying, The kingdom of heaven is at hand. Matthew 10:5-7
The Gospel of the Kingdom brings clearly into focus the third element of the Gospel of the Circumcision that God revealed to Abraham. The Gospel of the Kingdom explains in detail the governmental structure that will be put in place to make the people and land promised to Abraham a nation. Obviously, the roots of the Gospel of the Kingdom can be traced back to God's promise to Abraham, but it is in a promise to another Old Testament saint that we see it more fully expanded and explained. This explanation comes in the promise of Nathan, the prophet, to David.
And when thy days be fulfilled, and thou shalt sleep with thy fathers, I will set up thy seed after thee, which shall proceed out of thy bowels, and I will establish his kingdom. He shall build an house for my name, and I will stablish the throne of his kingdom for ever. I will be his father, and he shall be my son. If he commit iniquity, I will chasten him with the rod of men, and with the stripes of the children of men: But my mercy shall not depart away from him, as I took it from Saul, whom I put away before thee. And thine house and thy kingdom shall be established for ever before thee: thy throne shall be established for ever. I Samuel 7:12-16
David is promised that it will be his lineage that will rule over the people of Israel in the promised land forever. This promise is to be fulfilled not only in David's son Solomon, but ultimately in his son, Jesus Christ.
And the angel said unto her, Fear not, Mary: for thou hast found favour with God. And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS. He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end. Luke 1:30-33
During His earthly ministry, Christ made clear that he would not bring in the kingdom at that time, but would return a second time to establish the kingdom.
And as they heard these things, he added and spake a parable, because he was nigh to Jerusalem, and because they thought that the kingdom of God should immediately appear. He said therefore, A certain nobleman went into a far country to receive for himself a kingdom, and to return. Luke 19:11,12
This parable is a beautiful description of Daniel's prophecy concerning Christ's receiving of kingdom authority.
I saw in the night visions, and, behold, one like the Son of man came with the clouds of heaven, and came to the Ancient of days, and they brought him near before him. And there was given him dominion, and glory, and a kingdom, that all people, nations, and languages, should serve him: his dominion is an everlasting dominion, which shall not pass away, and his kingdom that which shall not be destroyed. Daniel 7:13,14
It must be noted that while the Gospel of the Kingdom was certainly very good news for the recipients of that kingdom, it was very bad news for those that would oppose the establishment of God's kingdom on the earth. In order for the kingdom to be established, the opponents of that kingdom must be destroyed. This is exactly what happens at the return of Christ.
And I saw the beast, and the kings of the earth, and their armies, gathered together to make war against him that sat on the horse, and against his army. And the beast was taken, and with him the false prophet that wrought miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone. And the remnant were slain with the sword of him that sat upon the horse, which sword proceeded out of his mouth: and all the fowls were filled with their flesh. Revelation 19:19-21
It is only after Christ has destroyed the opponents of the kingdom that His reign of peace can begin.
The Gospel of the Kingdom is good news about the coming of Christ to establish a literal, visible, physical, earthly, kingdom, sitting on the throne of His father, David.
The Gospel of the Grace of God
The Gospel of the Grace of God is a gospel message that is closely related to the Gospel of the Uncircumcision that we discussed above. The Gospel of the Grace of God is the message of salvation that is proclaimed to and by the Church, the Body of Christ, the topic of the Gospel of the Uncircumcision.
But none of these things move me, neither count I my life dear unto myself, so that I might finish my course with joy, and the ministry, which I have received of the Lord Jesus, to testify the gospel of the grace of God. Acts 20:24
It should not be surprising to find that the time in which the Gospel of the Grace of God is preached, is called the Dispensation of the Grace of God.
For this cause I Paul, the prisoner of Jesus Christ for you Gentiles, If ye have heard of the dispensation of the grace of God which is given me to you-ward: Ephesians 3:1,2
While it is true that God has, throughout history, offered grace to various individuals and groups. (See Genesis 6:8), the thing that is unique about the Dispensation of Grace is that God is offering grace to ALL men. That is why the Gospel of the Grace of God is so closely related to the Gospel of the Uncircumcision. Today grace is not being offered only to the physical descendents of Abraham, Isaac, and Jacob. All men, without distinction, have been given the opportunity to be reconciled to God through the Body of Christ.
But now in Christ Jesus ye [Gentiles] who sometimes were far off are made nigh by the blood of Christ. For he is our peace, who hath made both [Jew and Gentile] one, and hath broken down the middle wall of partition between us; 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; And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby: And came and preached peace to you which were afar off, and to them that were nigh. For through him we both have access by one Spirit unto the Father. Ephesians 2:13-18
For ye are all the children of God by faith in Christ Jesus. For as many of you as have been baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus. Galatians 3:26-28
The wrath of God that was to come to prepare for the establishment of the earthly kingdom has been withheld. Today God is not punishing the inhabitants of the earth for their sin and rebellion against Him. We can see a beautiful type of this offer of grace and mercy in the salvation and ministry of Paul.
And I [Paul] thank Christ Jesus our Lord, who hath enabled me, for that he counted me faithful, putting me into the ministry; Who was before a blasphemer, and a persecutor, and injurious: but I obtained mercy, because I did it ignorantly in unbelief. And the grace of our Lord was exceeding abundant with faith and love which is in Christ Jesus. This is a faithful saying, and worthy of all acceptation, that Christ Jesus came into the world to save sinners; of whom I am chief. Howbeit for this cause I obtained mercy, that in me first Jesus Christ might show forth all longsuffering, for a pattern to them which should hereafter believe on him to life everlasting. I Timothy 1:12-16
Paul was the chief of sinners. He was leading the persecution of the kingdom church in early Acts. So intense as his hatred for God's people that the Scripture tells us that he was "breathing out threatenings and slaughter" against them. Certainly if there ever was a man that deserved the wrath of God, it was Saul. But instead of pouring out judgement and wrath, God reached down in mercy and grace and saved Saul. He then sent him to the world with the Gospel of the Grace of God, a gospel of which Paul was a pattern.
The Gospel of the Grace of God tells the good news of God's wrath withheld. It offers grace, mercy, and peace to all men. It is the message of the Church, the Body of Christ in the Dispensation of the Grace of God.
Who's Got Your Gospel?
The gospel messages for today are the gospels proclaimed by Paul, the apostle of the Gentiles in the Age of Grace; the Gospel of the Circumcision and the Gospel of the Grace of God. It is the message proclaimed by these gospels that he refers to as "my gospel" and that plays a key role in our establishment in the faith.
Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began, Romans 16:25
We cannot be established in the faith and lead a life pleasing to the Lord if we are following another gospel. Our gospel message is found in the epistles of Paul, the apostle of the Gentiles.
Hope this helps someone.