The loss of God’s image is implied when Adam and Eve sinned. Do you think they would KEEP the image of a pure and holy God after they sinned and disobeyed Him? No way.
That is why the world needs a Savior. We are sinners who need to be saved (reborn Spiritually) so that we can be re-united with Him in heaven and regain the image of God we lost in the garden. Those who do not become born again, but who think they will go to heaven because they are “good people” will end up in hell instead. It comes down to whose righteousness you are trusting in: your own, or Jesus Christ’s.
But I won't change your opinion, and you won't change mine, so live your life according to your understanding. Please notice that my concept of Salvation goes far beyond what you require. 'The road is narrow that leadest to Salvation..." You 'born again' believers make it all too easy.
Read J.D. Salinger's short story 'Teddy'. It might open your mind a bit.