The email you provided is _ not _ from Pete Hegseth. It is attributed to an unnamed unit commander.
That matters because removing Hegseth alone would not solve the long-standing problem of this particular variety of apocalyptic white American Christianity in the US military.
Compare to the problems the same contingent caused when Bush 43 was POTUS.
(And Hegseth is Secretary of Defense, not "Secretary of War". It is important to not indulge his pretending otherwise.)
I have not found documentation of Hegseth personally subscribing to "the rapture" as a concept.
But he is a most definitely a Christian supremacist omnibigot who needs to be removed from the government before he kills more people than he already has.