The "gospel" cited in 1 Cor 15:3-4 doesn't mention who Christ is.Hopeful 2
Who is Christ according to the Gospel,
As for whose sins did He die for...all mankind's sins.whose sins did He specifically die for ?
1 John 2:2..."And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world."
Jesus provided the propitiation, as per 1 John 2:2 above.What did His dying for their sins accomplish for them He died for ?
Jesus' death also provided the means of casting off the "flesh" and being reborn of God's seed. (Rom 6:3-7)
It provided the way to be perfectly sinless.
The gospel does encapsulate more than one thing.The Gospel isn't just spouting out that one historical fact without explaining it in detail.
As 1 Cor 15:3-4 states three things..."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:"
Jesus died for our sins, was buried, and was raised from the dead.
Many more items would be added on that good news, as they were later revealed to His disciples.
But the gospel itself is three items.
It was the epistles that explained it in detail.