Science makes no absolute statements. Science is validated by the fact that it works.
I suspect the function of gods was originally to explain inexplicable things like thunder and lightning, drought and flood, good and bad luck at hunting, war, love, the status of the dead who could appear in dreams, &c, and to be a purported resource in times of trouble. But they also formed part of tribal identity, along with language, customs, stories, heroes and so on.
So you could say religion works as a tool of tribal solidarity ─ it was the same Christian God who was on both sides in Europe's wars, in WW1 and WW2, in Russia's present invasion of Ukraine, and much more. Or you could more accurately say that other things being equal, God is generally on the side of the big battalions.
And people die all the time, regardless of their views of the supernatural, regardless of peace or war, and as you know, we have no reason to think any part of their awareness or personality persists, though the wishful thinking that replaces it is quite polished after all these centuries. If you really don't want to die, keep your eye on science, which may conquer cancer at some time not unimaginably distant ─ though keep your eye on neurology too, since the world already has a sufficient number of senile folk.