By my current understanding there is pre-mortal spirit life and post mortal resurrected life, both of which are about theosis/ learning to become divine.
This is down to my (revealed, not logical) understanding that the basic purpose of creation is to enable/ encourage human spirits to become like our Creator and Father (i.e. at the same 'level' as him, so he can *fully* relate to us - this being his deepest wish, because otherwise his existence is relatively 'lonely' (although I also believe that God has a wife/ consort at the same level - i.e. our Heavenly , literal - tho not concrete, Mother) - or (to put it more positively) God may wish above all to live -ever-more abundantly - by the growth of loving relationships with a growing family of increasingly grown-up children.
This is naturally a vast task, and probably one taking an extremely long time/ great deal of experience and work - and never fully completed. But that is not a bad thing! rather it is what we are destined to do and our greatest conceivable and possible satisfaction. There is no hurry about this because it is a delight every inch of the way! (well, not every inch because of the suffering, but at every stage.)
Adding that there are things which can, at least by particular spirits, only be learned in this mortal incarnate life - not least by experiencing the negative side of things and through suffering - it seems a matter of common observation that (because of our free will agency) we find some thing very difficult to learn, and indeed - in practice, and over a finite timescale - some things we simply do not learn because we refuse to learn them.
To flesh out things in relation to reincarnation - my understanding is that most pre-mortal spirits need only what can be provided by a single mortal life; and that is the norm. But some need more than one life, and are offered the chance for another or more than another mortal life (always voluntary and chosen!); while others (who are, by one definition, mortal angels) have gained what they need from mortal life but choose to return to assist in this work.
As well as being united as children of the Father Creator (and Heavenly Mother) we really are and are meant to be unique individuals with unique paths all the way up to 'full' (but never finished) divinity!