Spiritualists say that each human being is an immortal soul that will survive his/her body. Some Biblical sects say that immortality can only be in a resurrected body. Orthodox Christianity combines these ideas so that there is both an immaterial hereafter immediately after physical death and a future resurrection of the body at Judgment Day. Valhalla was a cycle of fighting, dying, rising and feasting that would end at the Ragnarok.
References to these ideas remain in language even though many of us no longer entertain such notions.