If a Creator exists, then that proves that there are forces far beyond our comprehension at work. For example, I believe that God created time as we experience it, and so He exists outside of time. I can't believe that a universe has always just existed, because that doesn't answer the question of how it came to exist. If a Creator actually exists, then I can rest easy in the assurance that there's some explanation for His existence.
He didn't eternally damn the human race for this. God is holy and cannot tolerate sin - it would be like asking you to swim in a pool of acid. He gave humans the choice of whether or not to trust in His assessment of what is right and wrong, and they eventually chose not to trust this - they wanted to see right and wrong through their own eyes. Once they had done so, they were sinful, as we now try to decide for ourselves what is right and wrong. Because God is perfectly holy and perfectly just, sin cannot go completely forgiven, but must have consequence. For centuries God let His people try to atone for their sins, but we aren't perfect and no matter how hard we try, we fall short of His perfection. So instead of the constant "sin-atone-forgive" cycle that is the subject of the OT, God chose to pay the price of sin for all of us, one time. He let Himself be killed as a human, so that we can be forgiven without the constant cycle of trying to keep up with perfection. We instead are forgiven forever when we accept that His sacrifice was sufficient for our sins. In this way, He actually shows His love for us - trying to find a way to allow Himself to share relationship with us even though we are sinful.