The "objective" code of morality that your Christian friend cites is not objective in any way. His holy book contradicts itself on morality so many times that every Christian is forced to pick and choose which parts to follow. Objective would be if God did an interview on Larry King Live and said EXACTLY what humans are not allowed to do, without sending his message through humans (which has been a grave mistake God keeps making again and again). Rather, his various human mouthpieces contradict each other frequently on the issue of morality even within just one religion, not to mention disputes between, say, Christianity and Islam.

Objective morality does not exist, with or without God.