Traditional Christians are often salvation-focused; and may be hostile to ideas of theosis (regarding it as an heretical belief in salvation by works); may ignore theosis almost-entirely in their overwhelming desire for salvation at the end of life; or else may conceptualize theosis (or variant concepts such as sanctification deification, spiritual progression, exaltation) as "merely" a means to the all-important end of salvation.
On the other side "spiritual but not religious" people (including the "anything-but-Christianity" kind of spiritual people) are often focussed upon theosis while rejecting the need-for or desirability-of salvation - their end-point is not resurrected Heavenly life, but reincarnation, or some sort of oneness-Nirvana.
The basic stance is that this life is (or ought to be) about continual spiritual self-improvement; and that to introduce considerations of what happens after death is a contamination of spiritual purity by an ego-driven desire for self-gratification.
My understanding is that salvation and theosis are indivisible - that we must both aim-at resurrected eternal life, and also live this mortal life such that we learn-from its experiences.
This may be made clearer by regarding salvation as the purpose of life and theosis, as the meaning of life.
Distinguishing-between purpose and meaning is a perfectly valid thing to do; yet ultimately they are indivisible and we cannot have one without the other.
The purpose of life is what makes meaning possible within that purpose; and the meaning of life is how purpose actually manifests in life.
When not-Christians pooh-pooh the Christian demand for salvation as the purpose, they also obliterate any possibility of coherent meaning; and spirituality degenerates into merely a kind of self-therapy, which itself becomes indistinguishable from pleasure-seeking or suffering-avoidant hedonism - as can be seen with the New Age movement.
And when Christians revile, neglect or subordinate theosis and "the spiritual" they destroy any ultimate reason for continued mortal life - mortal life becomes a negative thing - a double-negative attempt to avoid sin (which, Jesus tells us - and Paul) is impossible; and a mere waiting for death that is an implicit denial of the validity of God's creation.
But when salvation and theosis are understood as indivisible purpose and meaning of this mortal life; then we have a solid basis for a properly aimed and fulfilling existence here on earth.
