Is changing my dads mind the right thing to do?

[Leumas]

If what's been the psychological push for him to embrace his born-again faith is having failed at his one single life, then he might lap up the religions that teach reincarnation, because that will mean this is only one of many lives, so that there's more than enough time, through eternity, and through countless more lives to come, to make up for anything left undone in this one.

On the other hand, that would, even if it worked, only be swapping one irrational faith for another, so maybe not much point to it.

In fact ... there is a point... some irrational beliefs are less impactful on the health of the globe than others... the three religions based upon the peripatetic Sumerian guy who went around Canaan peddling his half-sister-wife's "beauty" are definitely more harmful than Jainism.

If he's only in his fifties, like you say, that means he still has a whole lifetime left to live (by earlier times' standards, I mean --- assuming an expectancy of say 85, that's still some thirty years more). It would be silly of him to waste all of that time with this nonsensical preoccupation of his, so that, absolutely yes, you'd indeed be doing him a favor by helping rid him of that irrational superstition....

very good point.