In philosophy and theology, what is meant by the phrase "passing over and coming back"?

In contemporary philosophy and theology, the term “passing
over and coming back” seems to be associated with the theologian John Dunne, who in 1972
wrote that the modern holy man would seem to be a
person

like
Gandhi, a man who passes over by sympathetic understanding from his own religion to
other religions and comes back again with new insight to his own. Passing over and
coming back, it seems, is the spiritual adventure of our time. [see links
below]

The phrase has since
been used by many other people in many different contexts, as a search for this phrase,
using Google Books, will show [see links below]. In general, though, the phrase still
seems to be largely understood as Dunne used it.  “Passing over and coming back” thus
means acquainting oneself with what other religions teach, but without abandoning one’s
own religion. The perspectives provided by an honest attempt to understand other
religions can enhance one’s own religious
experiences.

“Passing over and coming back” seems to differ
from “empathy,” which is defined by href="http://oxforddictionaries.com/definition/empathy?region=us">www.oxforddictionaries.com
as “the ability to understand and share the feelings of another”
(emphasis added). “Passing over and coming” back implies the ability to understand other
religions without necessarily sharing in them completely.  After all, “coming back” to
one’s own religion is an explicit part of the idea. “Passing over and coming back” also
seems to imply an emphasis on understanding rather than simple
feeling.

Given the fact that we live in an increasingly
multicultural society in which globalization is also a major feature, it is not
surprising that an understanding of other religions has become increasingly
important.