The gospel of Christ is opened up by John the Baptist here:
Luke 3:15-18 (KJV)
15 And as the people were in expectation, and all men mused in their hearts of John, whether he were the Christ, or not;
16 John answered, saying unto them all, I indeed baptize you with water; but one mightier than I cometh, the latchet of whose shoes I am not worthy to unloose: he shall baptize you with the Holy Ghost and with fire:
17 Whose fan is in his hand, and he will throughly purge his floor, and will gather the wheat into his garner; but the chaff he will burn with fire unquenchable.
18 And many other things in his exhortation preached he unto the people.
How was the gospel of Christ preached next? Matthew 4:12-17 (KJV)
12 Now when Jesus had heard that John was cast into prison, he departed into Galilee;
13 And leaving Nazareth, he came and dwelt in Capernaum, which is upon the sea coast, in the borders of Zabulon and Nephthalim:
14 That it might be fulfilled which was spoken by Esaias the prophet, saying,
15 The land of Zabulon, and the land of Nephthalim, by the way of the sea, beyond Jordan, Galilee of the Gentiles;
16 The people which sat in darkness saw great light; and to them which sat in the region and shadow of death light is sprung up.
17 From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand.
Yes, of course the condition of belief unto salvation for us is to believe Jesus died and rose again the third day, confessing that to men. But it that the sum of our salvation? Before answering, consider those two passages above and how we figure into them.
I ask another question in an ongoing answer to the OP. Upon what did Jesus build his Church? His death and resurrection? My answer is what happened to Simon "Peter" when Jesus asked the disciples who they thought he was. Peter acted upon revelation, telling the true identity of Jesus as Son of God. But Jesus prohibited them from telling that information to anyone else. Matthew 16:15-20 (KJV)
15 He saith unto them, But whom say ye that I am?
16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God.
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.
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.
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.
20 Then charged he his disciples that they should tell no man that he was Jesus the Christ.
Was Jesus forbidding to tell part of the gospel? Why tell them that? Why not tell hem to preach of his coming death and resurrection? When Peter comprehended that might be about to happen, he took Satan's part. The primary fact that Peter knew the truth, that a man comprehended that revelation without being taught it, Jesus was finally spiritually recognized and absolutely known, as natural men can't do.
So how do we 2,000 years later, enter into that Kingdom and it's benefits? The same way Peter saw that light, having heard the gospel preached by Jesus, then believing it. On the other side of the cross Peter, Paul, and many others realized by revelation what it took to remove that veil in the Temple, that all who would believe on Jesus and all that his Kingdom is, that He is the Door through his death, shedding his own blood, and rising from death to the law of sin and death, all men can be saved through him. "The Way" of Christ Jesus is summarized , in as manner akin to the Ten Commandments summarizing the heart of all the Law, in this: John 10:7-11 (KJV)
7 Then said Jesus unto them again, Verily, verily, I say unto you, I am the door of the sheep.
8 All that ever came before me are thieves and robbers: but the sheep did not hear them.
9 I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture.
10 The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly.
11 I am the good shepherd: the good shepherd giveth his life for the sheep.
There's the gospel straight from Jesus. Or, it can be realized by true belief in Acts 2:21 (KJV)
21 And it shall come to pass, that whosoever shall call on the name of the Lord shall be saved.
Equally powerful are the several scriptures offered by others of us here. My point is that the Kingdom of Heaven includes all that Jesus is and is about, and believing on Him who raised Jesus from the dead. .
So I must reject your OP case, as all things written of Jesus are part of the gospel of Christ, as well as each person on earth should know Jesus is the Christ, the Son of the living God by revelation of the Holy Spirit. Then when you confess Jesus with your mouth, you mean it from the mind and with all your heart.
