For da-man,
Your question about what happened before the law is answered in
Hebrews 11.
It said that those before the law were saved from their sins the same way those in the Christian era are...
...by faith in the one true God.
Also,
Romans 1 gives us an interesting angle regarding those evil who existed before the law. It said that some denied Him.
How?
By rejecting what they knew in their conscience and saw in creation (
Romans 1:18-20.)
I deal with a similar subject on my website...
www.bible-student-online.org
Hope this helps.