The gospel is about the sinful state of people, what Jesus did to atone for sins, and how God's grace is accessed through faith in Christ.
For us today 1cor 15 -1-4 . Rom 10 ,9 Eph 1.3 is the good news we preach.
luke 9.6 Gospel did not include what you said here //The gospel is about the sinful state of people, what Jesus did to atone for sins, and how God's grace is accessed through faith in Christ.//
Look at luke 9.6
And whosoever will not receive you, when ye go out of that city, shake off the very dust from your feet for a testimony against them.
6¶And they departed, and went through the towns, preaching the GOSPEL , and healing every where.
This is way before the cross and resurrection.
So ' the gospel ' doesn't always mean the DBR for our sins .
Nor does rev 14 say that either.
Gospel means ' good news ' .
Its not a blanket phrase with one meaning . ' Good news ' . About what? is the question to ask .