What was the Good News that St. Paul gave?

Answer 1

Paul, in writing a letter to the Christians at Corinth, says this (remember that "gospel" means "Good News"):

"Now, brothers, I want to remind you of the gospel I preached to you, which you received and on which you have taken your stand. By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain. For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures, that he was buried, that he was raised on the third day according to the Scriptures, and that he appeared to Peter, and then to the Twelve {disciples/His closest group of friends}. After that, he appeared to more than five hundred of the brothers at the same time, most of whom are still living, though some have fallen asleep {died}. Then he appeared to James, then to all the apostles, and last of all he appeared to me also, as to one abnormally born." (1 Corinthians 15:1-8)

Basically, the Good news is that Jesus died for our sins and is alive today, and this is proven in the fact that many people (over 500!) saw him after he rose from the dead.