And why has nobody mentioned Shinto? Oh wait, this thread was from 2011? Well too bad.
Any religion that contains moral strictures against theft, ala 'you shall not steal' contains within it the premise of private property. So there's that at least for Christianity.
The typical christian case for socialism is post-crucifixion voluntary communes among the new faithful--however it's important to point out the voluntaryism of this group, and that government was never involved at all.