According to the Bible, satan had been cast down to earth to tempt, torment and distract everyone who was ever born. If any single person, (Adam or Eve) gave into temptation even once, God handed over the fate of all their descendants to the hands of satan and basically sealed the book on the fate of billions that they would have an eternal existance of pain and suffering.

If God really loved us, why would he allow satan to roam free or to even exist in the first place? And even if satan was allowed to roam free, why is everyone born condemned because of one event that happened thousands of years ago?

(extracted from common questions found online)