@ Vienne - Your statement that JW's don't specifically teach that the 144,000 are part of the ransom doesn't alter WHAT they believe nor their BASIS for that belief, namely, that Jesus' death & sacrifice ALONE enabled a "heavenly class" of humans.
If not, JW's would have to explain why Abraham, Moses, Elijah etc.aren't in heaven.
(Luke
22:20) Also, he did the same with the cup after they had the
evening meal, saying: “This cup means the new covenant by virtue of
my blood, which is to be poured out in your behalf.
(John
6:53) So Jesus said to them: “Most truly I say to you, unless
you eat the flesh of the Son of man and drink his blood, you have no
life in yourselves."
Don't forget, it's only the "upper class" HEAVENLY Christians who are invited into this covenant, while the "lower class" EARTHLY Christians will "benefit" from the crumbs falling from the heavenly table.
To reinforce the OP title - scripture PROVES scripture:
(Psalm
45:16) You will appoint them as princes (not kings)
in all the earth. (not heaven)
(Revelation
5:10 – K.I.T.) ...and you
made them to the God of us kingdom and priests, and they are reigning
upon the earth.” (no mention of them being kings,
and they're upon
the earth – not over it!)
The "heavenly class" is a falsehood and perverts the value of the corresponding ransom.