Well you know the main reason Christianity spread so far, dunt ya?

The Roman Empire. A new form of control. A modern one. To save their flailing empire. Though of course, the Emperor at the time (name slips my mind) may have 'found the light' while he was at it.

Religion has always been a good form of order. The tyranny of order over the tyranny of chaos. And then used furthermore to further political-power ambitions.

Tis more so the humanity (in general) in religion that corrupts it. Rather than the religion itself.

Though even religion itself can be corrupt. Things that are written in their 'scriptures' that are seen as wrong today. By even those of it's religion. And i mean the 'highest' of that religion. But they are buried beneath all the other stuff. The 'better' sides of it.

There's a 'religion' followed by over a billion people. Yet it is concentrated mainly in one country. Though one could argue VERY strongly, that if it was imposed worldwide. It'd be much more open to corruption. And even 'openly' encourage it. Yet it's welcomed as a very good alternative to the mainstream religions of today. By left wingers, liberals etc. It could be the most wide ranging religion of humanity. Touching on every aspect of it (both good and bad). As it branches out like that...

It goes on and on...