Excerpt from Houdini's "A Magician Among the Spirits" (1924). For more, see.

[Doyle] stated that there is a plane called "Paradise" where
"normally respectable" persons go after death and this
"plane" is only slightly removed from this earthly sphere.
Bad people when they die are transported to a plane considerably
lower than that tenanted by respectable ones
and they continue to sink lower and lower unless they
repent. Mter a considerable probationary period they
are able to climb into "Paradise." The average length of
time they stay in "Paradise" is about forty years after
which they float to higher and still higher planes. All
mediums have guardian angels to whom they are especially
subject, but they can communicate with other Spirits,
the "guardian angel" acting as a sort of master-of-ceremonies
upon such occasions.