Then gradually the pure Christian concepts were absorbed into the established god-king system.

That is a place - similar to the Christian concept of heaven - where nirvana can be achieved.

It is often given in reference to the Christian concept of divine grace and used as a virtue name.

This concept is most similar to the Christian concept of incarnation.

Islam says the Christian concept of original sin is false.

You're saying that the Grail is not a Christian concept at all.

Consequently, the natives incorporated more Christian concepts into their belief system.

The key Christian concept in all these areas is that of stewardship.

It is not to be confused with Christian concepts of Hell.

It is similar to the Christian concept of a guardian angel.