Sounds like a movie plot.
Yep, a bit like "Strangers on a Train" by Hitchcock.
Do you mean that such a swap has already worked first time around so that B has become saddled with A's responsibilities which B now wants to get rid of? Was the swap consensual? Because it sounds a bit like a curse… why do these responsibilities have to be transferred back to A? Why not simply shrug them off and be done with them? Is there some kind of pact between A and B? Do those heavy spiritual responsibilities involve solemn vows or something equally binding?
I for one don't believe in a providential and caring universe, and that's why I think it's solely between A and B, without the possibility of any higher power interfering. A and B have to come to terms in this matter and agree that no divine authority or whatnot can dictate how to their lives, so the problem would be solely between the two of them. They could even end up sharing those responsibilities, and B could teach A a lot about being more assertive.
The debate of predestination vs. free will has been going on for at least 2,000 years and I'd hate to start a new one here but if you really believed in predestination, then your fate would inescapable anyway, including both a failed and successful reverse destiny swap. In my opinion, you should ditch the entire model and opt for a more fluid one where nothing is set in stone and nobody has the right to put (imaginary?) burdens on either A or B.
In postings asking for advice, there are usually more factors and variables involved than is apparent. A and B may be in a romantic relationship together. A may be the boss of B. A and B might be siblings. A may be convinced of the destiny thing because of his or her natal chart while B thinks astrology is bullshit. We may discuss solutions among us that are completly unapplicable or inappropriate in this situation without us being even aware of it.
