In my life, I have said that I would not undergo a 'deathbed conversion' to any religious creed. This, my last promise that I could possibly have kept, I kept indeed.
To those who say that I did not keep my word, I say this: A deathbed conversion is of no value whatsoever. Even if such a conversion does occur, what does it prove? It certainly does not prove the validity the faith to which the new adherent swears his brief allegiance, nor does it prove the invalidity of any competing faith to which the dying person chose not to convert. The validity of religious tenets must surely be established by their merits and their effects, not by the number of dying men who suddenly attest to them.
Such a conversion may easily be attributed to fear or a loss of mental acuity, both of which often precede death. Or it may have done as a courtesy to the family, who fear that the departing loved one will be lost in the afterlife, unless words of conversion are uttered. To the dying person, it may be like a perverse Pascal's Wager, except that the payoff is not eternal life but rather is less pointless worry by loved ones.
I suggest that a far more potent conversion is the post-death conversion. A person who has died, and who thereby may have acquired knowledge of use to those still living, may relate that knowledge so that conversion may be made to the correct faith in the proper course. In my life, I was aware of no instances in which post-death knowledge was imparted to the living. The play of Hamlet, in which such knowledge plays a pivotal role, is of course fiction.
Nevertheless, in the event I find that I was wrong, I shall make an effort to correct my error. I shall make a post-death conversion and will try to relate what I have learned. I shall do my best not to be as terrifying as the ghost of Hamlet's father.
But don't stay up late at nights just to wait for me.