The theme of the Epistle to the Romans.
Yea, the theme by extension of all 13 of the letters of Paul to gentiles.
It is stated clearly and pointedly in verse #1. Read it with me.
Romans 1:1-6
1 Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God,
2 (Which he had promised afore by his prophets in the holy scriptures,)
3 Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh;
4 And declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead:
5 By whom (Jesus Christ) we have received grace and apostleship, for obedience to the faith among all nations, for his name:
6 Among whom are ye (at Rome) also the called of Jesus Christ:
If one does not get this theme and understand it he has zero chance of having a comprehensive understanding of the epistle to the Romans or the ministry of Paul.
In verse 1 he is separated from the other apostles. They are called to minister to the circumcision. He is called to minister to gentiles.
What is the gospel of God? Is it the same as the gospel of Jesus Christ? If it were Paul would have said so. It contains the gospel of Jesus Christ but it is much broader and specialized in its application. Remember, gospel means good news, glad tidings. He would still be preaching the gospel of Jesus Christ because it is the gospel of salvation to both Jew and gentile. Look.
Romans 1:16
For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one that believeth; to the Jew first, and also to the Greek.
For the most comprehensive definition of the gospel of God, read this quote below.
Romans 16:25-27
25 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,
26 But now is made manifest, and by the scriptures of the prophets, according to the commandment of the everlasting God, made known to all nations for the obedience of faith:
27 To God only wise, be glory through Jesus Christ for ever. Amen.
There is much to talk about here but he mentions obedience of faith again. The nations are commanded to believe the gospel of Jesus Christ. The good news, glad tidings of God is that he has now revealed his “mystery” that he had kept hidden from the creation of the world until now. That is the mystery of Christ which he reveals in full in Ephesians. The Theme of Ephesians is the mystery of Christ and one verse gives the comprehensive view of it. Read it with. I will quote the verse and trust the reader to read the context. It is V6.
Ephesians 3:3-7
3 How that by revelation he made known unto me the mystery; (as I wrote afore in few words,
4 Whereby, when ye read, ye may understand my knowledge in the mystery of Christ)
5 Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;
6 That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel:
7 Whereof I was made a minister, according to the gift of the grace of God given unto me by the effectual working of his power.
That is the mystery revealed and implemented in time. Paul was not even saved until AD 37. He was made particularly the apostle to the gentiles and trained by God by means of special revelation. This means he understood things about the church the other apostles did not know.
We also learn the gentiles had no promises of salvation made to them therefore they had no hope and were without God and Christ. This is the reason the operative principle of Divine dealing with them now was “grace” and called salvation the “gift of God.” The Jews as long as they had their national identity and dwelt in their own land were being dealt with under the operative principle of promise. They had continually in their history been promised salvation and Jesus said to them, “I came not to destroy the law and the prophets but to fulfill.” Therefore do not be surprised to see the word promise pop up all over the place when they are the subject of salvation. Just count the times in Ga 2 as a for instance.
Well there is so much I could tell you about these wonderful truths but I want to quote the places Paul speaks about the gospel of God. Seven times it is called the gospel of God and three times he calls it my gospel for a total of ten. You will always find the number 10 associated in scriptures with gentiles. First read this.
Acts 17:30
And the times of this ignorance God winked at; but now commandeth all men every where to repent:
31 Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead.
Romans 1:1
Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God,
Romans 15:16
That I should be the minister of Jesus Christ to the Gentiles, ministering the gospel of God, that the offering up of the Gentiles might be acceptable, being sanctified by the Holy Ghost.
2 Corinthians 11:7
Have I committed an offence in abasing myself that ye might be exalted, because I have preached to you the gospel of God freely?
1 Thessalonians 2:2
But even after that we had suffered before, and were shamefully entreated, as ye know, at Philippi, we were bold in our God to speak unto you the gospel of God with much contention.
1 Thessalonians 2:8
So being affectionately desirous of you, we were willing to have imparted unto you, not the gospel of God only, but also our own souls, because ye were dear unto us.
1 Thessalonians 2:9
For ye remember, brethren, our labour and travail: for labouring night and day, because we would not be chargeable unto any of you, we preached unto you the gospel of God.
1 Peter 4:17
For the time is come that judgment must begin at the house of God: and if it first begin at us, what shall the end be of them that obey not the gospel of God?
Romans 2:16
In the day when God shall judge the secrets of men by Jesus Christ according to my gospel.
Romans 16:25
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,
2 Timothy 2:8
Remember that Jesus Christ of the seed of David was raised from the dead according to my gospel:
One can see this is thematic in the scriptures. There is much more to know but the take away of this post is that God has opened the door of faith to gentiles and commanded they believe in Christ. This requires obedience and at once demonstrates that believing is an active verb. It is an action. It is a response, the proper response to God. The preaching that a sinner cannot respond to God by believing the gospel like he commanded will send some people to the lake of fire. You had better not pervert the gospel of God.