Simply put, the gospel is the “good news”. And the good news is this… that God, the creator of the universe, is good, and desires a personal relationship with each one of us.
Unfortunately, mankind is bent toward the dark side, and basically toward everything that God is not. As a provision for this, in order to have that intimate relationship with us, God sent His own son, Jesus Christ, as a willing sacrifice, to suffer and die for all of our wrongs, making full payment for them. And then He conquered death for us, raised from the dead and ascended into heaven… making a way for us to enter heaven as well.
The one requirement that God has made, is that we simply believe what He said to be true, turn away from our old life, and receive His Son, Jesus, into our hearts by faith.
God then begins a new life inside of us, changing us and conforming into His own image… And then ultimately granting us the incredibly wonderful gift of eternal life with Him, the angels, our loved ones and all true believers… in Heaven!