my father is religious, I’m not and I don’t care what happens to my body after I die. Burn me, use me to feed stray cats.
To me, wasting money to buy a plot of land so I may be buried with them when I die is a stupid idea.
It is, however, his money. Who am I to disagree with him?
He can do what he wants, but you can also do what you want. I’d play along. Chances are, he won’t be there to argue with you when you go.