is execution of punishment or is it just a method to get rid of dangerous individuals?
It’s neither. The dangerous individuals have already been removed from society so killing them is unnecessary. And, as you’ve pointed out, a life sentence is a much better punishment so executions aren’t about punishment. It’s not a deterrent, as some advocates suggest, since the homicide rate is higher in states with the death penalty than those without.
Ultimately, the purpose of executions seems to be revenge. I think there’s more nuance than that but every time I attempt to express it I discover that I can’t do so succinctly. I sincerely apologize to anyone that might read this and feel like I’m misrepresenting their position.
If they haven’t made a public statement that they’ve stopped excluding atheists, why should anyone assume they’ve changed their policies?