As far as I can see it, certain theology needs people to be able to choose God.
For them the sin of unbelief in Christ sends them to hell.
That will not work if people cannot choose.
By the way they do not believe people are lost in sin or blind, because Christ has
forgiven all sin for the whole world.
It is this part of their belief system they actually leave out sharing.
So when people argue like it is life and death over one issue, for them it might
very well be because their belief system collapses without it.
It is like when you suggest Jesus is God to a muslim, to believe this in their world
is a death sentence. It is why if people understand their culture, things are not
neutral or nice to believe, your own family may try and kill you if you believe them.
So when someone is particularly sensitive about something obscure, they are hiding
why this obscure issue is everything, though they will claim they are just like "normal"
believers, you can tell they are far from that.