We know Chuck was lying because he created the Garden. He was just looking for any excuse to avoid helping Jack and to further manipulate Dean into killing him.
When [[God]] created the world, He created the Garden of Eden as a crossroads between humanity and divinity, where he kept His prize creations Adam and Eve. However,
because of an unspecified reason, they were banished from the Garden along with the rest of humanity. The Garden of Eden was hidden away, and appears to exist in an alternate realm outside reality. The Garden can be accessed if a non-human entity consumes [[the Occultum]]. According to [[Castiel]], the Garden is "the crossroads of divinity and humanity" and no one has been there since the exile of humanity.
Within the Garden is a young girl and an albino python snake. The young girl appears to have great knowledge of the Garden, but her actual purpose is not known. The snake or the nature of the Garden itself appears to have the ability to restore [[souls]] in [[soulless]] people
, something that even God Himself claimed He was unable to do.