I wouldn't call Christ a con artist, he preached against the greed of organised religion and said that you didn't have to be in a church to love your God, which was got him killed in the end. Modern Christianity really doesn't reflect Christ's words as I understand them.

I also personally have the belief that all the religious books are written around the same principles but colloquially they differ. For example who Europeans call God, Muslims would call Allah and Jew's Jehovah. Who knows eh? Maybe I'm wrong.

Also, If you look at a lot of founding principles in religion they served a purpose, they may not be as important in this day-and-age but they were then. For example, Jewish people not eating shellfish: my take on this is that it's very unsafe to eat bad shellfish and before refrigeration there's every chance it would go off quickly! So 'God says avoid' gets through and spares life.

The same can be said for other do's and dont's.