It is a translation of Buddhism Sutta. Not a text of 19th century. Right?
It is apparently a translation of a passage from Mara Upasatha Sutra - but you didn't know that did you? You just cut and paste from a web version of a 19th century English compilation of supposed sayings of Buddha. I have read that book (the 19th century "Gospel of Buddha" - I have a PDF version on my PC - its a great story). I have no idea how long after the supposed life of Buddha this 'event' was committed to writing - but my guess is it would be somewhere between 2 and 5 centuries. So we really have no idea whether Gautama Buddha really said that or whether a slightly less ancient sage made it up. In any case...
Only in Scriptures of great religions, you can find 'dead', and 'living', having this figurative meaning, and only those scriptures that Bahai Scriptures confirm to be from One God.
Well that I don't know. I am not going to spend a lot of time on it because
(a) even if you are right (to some extent at least) it still doesn't follow that using the same literary devices makes one the same person as another - if we take the idea of a resurrection as an example, that would presumably mean that Shakespeare, Tolkien, Dickens and J.K. Rowlings are all the same person...and
(b) I have no idea whether the word translated "quickened" meant a "figurative" or "spiritual" "resurrection" because that word can also simply mean "enlivened" or "invigorated"...etc...and given that Buddhism has no concept of a bodily resurrection (as in the main sects of Abrahamic religions) I see no reason why they would have used such a figure of speech in that way. On the other hand, if it was simply indicating that it was "as if" the Monks had returned to life after hearing the Buddha's discourse, well I don't think that really stands out as particularly special...
...anyway, really, you have so far presented only a similarity between one short passage of Buddhist "scripture" and an interpretation of Christian scripture that is not held by the majority of professed Christians (namely that the resurrection is purely figurative)...I think rather than asking me about what Joseph Smith etc. may or may not have written on the subject, you should be asking yourself whether you can find any Hindu, Zoroastrian...etc. scriptures which use the same metaphorical language. That might, perhaps, lend a bit more credence to your argument, but so far all you seem to have is:
"...two religiously important figures of ancient times were reported to have used a possibly similar figurative sense of the word "dead" and/or "resurrection" "
It is an enormous leap from that to "therefore they were the same person...namely, God"!