The New Testament! …all that Jesus taught.
Thats not our gospel here is the gospel for today
This is the gospel by which we are saved.
1 Corinthians 15 contains Paul's gospel:
[1Co 15:1, 3-4 KJV] 1 Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; ... 3 For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; 4 And that he was buried, and that he rose again the third day according to the scriptures:
We are all sinners who cannot save ourselves.
See Romans 3:23 Titus 3:5 Romans 5:6
[Rom 3:23 KJV] 23 For all have sinned, and come short of the glory of God;
[Tit 3:5 KJV] 5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost;
[Rom 5:6 KJV] 6 For when we were yet without strength, in due time Christ died for the ungodly.
Christ died for our sins; He was our substitute; He paid the full penalty and debt for our sin by his blood sacrifice.
See 2 Corinthians 5:21 Romans 3:24 Romans 3:25 Romans 3:26
[2Co 5:21 KJV] 21 For he hath made him [to be] sin for us, who knew no sin; that we might be made the righteousness of God in him.
[Rom 3:24-26 KJV] 24 Being justified freely by his grace through the redemption that is in Christ Jesus: 25 Whom God hath set forth [to be] a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God; 26 To declare, [I say], at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.
He was buried.
He rose again for our justification (to declare us righteous) and forgiveness of all our sin. He gives us His righteousness and eternal life.
See Romans 4:25 Ephesians 1:7 Romans 4:22 Romans 4:23 Romans 4:24 1 Corinthians 1:30
[Rom 4:22-25 KJV] 22 And therefore it was imputed to him for righteousness. 23 Now it was not written for his sake alone, that it was imputed to him; 24 But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead; 25 Who was delivered for our offences, and was raised again for our justification.
[Eph 1:7 KJV] 7 In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace;
[1Co 1:30 KJV] 30 But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption:
All we have to do is believe the gospel.
See Romans 4:5 1 Corinthians 1:21 Ephesians 1:13
[Rom 4:5 KJV] 5 But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness.
[1Co 1:21 KJV] 21 For after that in the wisdom of God the world by wisdom knew not God, it pleased God by the foolishness of preaching to save them that believe.
[Eph 1:13 KJV] 13 In whom ye also [trusted], after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
Believing is being persuaded that something is true.
See Romans 4:20-22
[Rom 4:20-22 KJV] 20 He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God; 21 And being fully persuaded that, what he had promised, he was able also to perform. 22 And therefore it was imputed to him for righteousness.
The moment you believe you have eternal life.
Titus 1:1 Titus 1:2 Titus 3:7
[Tit 1:1-2 KJV] 1 Paul, a servant of God, and an apostle of Jesus Christ, according to the faith of God's elect, and the acknowledging of the truth which is after godliness; 2 In hope of eternal life, which God, that cannot lie, promised before the world began;
[Tit 3:7 KJV] 7 That being justified by his grace, we should be made heirs according to the hope of eternal life.
Trust the gospel of your salvation. Place your faith in Jesus Christ, in his blood, in his death and his resurrection