Eight is twice four, which means that it carries twice four's stability and worldliness. Eight follows seven, which is the number of life in this world, so 8 is often seen as the number of life after death.

Eight has four's capacity for dazzling defeat, but it also has a capacity for big big success (because it's twice as big as four). Therefore eight is big in Christianity, where after death we have the possibility of either massive failure (hell) or big-time success (heaven). Eight's ties to the afterlife are also the reason that the infinity symbol is an 8 on its side.

Eight people are worldly and solid. They may fail miserably or succeed wildly, and of course the numerologists will tell you that this depends on the rest of your numbers. Now, if you have a nine in there....