God is a debatable entity and the existence of god can nether be denied nor be proven. But there are subtle usage of the God and theorists link few things to god to make the theory convincing at least in the eyes of the people who have too much of religious stuff in their head.
Almost all the 2021 doomsday theories have element of god linked from one or another angle. There are many 2012 theories which claim to have based upon either Bible or some other book. The intelligent heads are seeing good commercial use of god to cash money. Good indeed! and Oh God!. Nobody knows whether God created man or man created god. But if the equation is petty much in favor of the people who cook something like absurd theories and make them convincing with the help from elements related to the god.
So, what is the role of god in 2012? Apparently, it is not more than 2010 or WWI or WWII. Not really willing to debate the authenticity of God. The point is, 2012 will be derived from the previous years and the largely events are predictable and can be explained.
Many people think that god is going to help to make the world a better place in 2012. If it is about new technologies, one may agree. But it these theorists are talking about humanity then there are serious doubts. Human history has been like this. You can pickup any random year from the past and you would find many events of bloodshed, crime etc. The exact point is, nothing of such is going to vanish from the world in 2012. The international and regional conflicts will not be solved in 2012 and the nature of the conflicts point to the fact that few of them will not be solved ever.
Let god be an entity which is worshiped all over the world. The commercial use is one thing and but to prove your absurd points with god related theories, is more idiotic and plain stupid.