Christian Universalism - interesting concept

Ok, Pro-christian readers can comment. I'll try and be nice.

Just because something flies in the face of everything one knows to be true, doesn't make it wrong. I'm not calling myself a universalist but I am intrigued by the idea of it.

"...just as the result of one trespass was condemnation for all men, so also the result of one act of righteousness was justification that brings life for all men." Rom 5:18

Did Paul mean that even though the single sin of Adam was enough to damn the entire human race, the single act of righteousness of Christ was NOT ENOUGH TO SAVE ALL MEN?
Was Adam's sin MORE POWERFUL than Christ's salvation? Was Adam able to bring more "death," and this universal death has overwhelmed the weaker "life" that is found in Christ?

Therefore... Will ALL men be saved or only the small sliver of people who happen to follow the correct instructions? Is eternal life ONLY for the Christians?

If so, then Jesus truly did save the world through his very temporary death. If not, then God is responsible for billions of deaths and Hell (whatever that is) will be full up. Big questions.