Sometimes we make things much more complicated than they need to be. Entire books have been written to explain the gospel, but here is how the Apostle Paul summed it up in four sentences:
"Now, brothers and sisters, 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." 1 Corinthians 15: 1-4 (NIV)
Nothing I could add will make it any clearer than Paul did two thousand years ago.