Remember the FLOOD?
There must of been people in this world who weren't following the rules. This is a test of patience from God. If you can handle this he will give you a reward. This is actually from the muslim point of view so yeah.
God once said that when everyone in the world turns to god the earth will melt like snow and everyone will live in his kingdom. Till then, people are still on this earth so when they die they go to heaven. (If the person believes in god.)
Obviously you didn't read the bible.
Here's a link to a similar topic, hope it helps...