I'm agnostic and I'm extremely happy. I make the most out of my life, despite challenges, treat everyone that I can with kindness and live every day as best I can. I respect all religions, do not question their validity, and find beauty in the diversity of cultures around the world. However, I have never found it necessary to conform to a specific religion or believe in a certain god. This has not stopped my from being moral and kind- I'm sure it would be the same for most.
It would be complete anarchy, literal hell on earth. In fact after the rapture, we will get to have 7 years of no God on earth with the anti-christ ruling. Read the scripture and study them to see how bad the tribulation will be and will get a sense of what a world without God is like.