It is one of the most profound, yet simple, insights of Mormon theology that to be incarnate - embodied - is a higher state than being a pure spirit.
The idea is that God is incarnate, and that this mortal life is primarily about 'getting a body' - the work of Jesus Christ was (in part) to enable all men to be resurrected, and live eternally incarnate (and cleansed of corruption).
This was a breakthrough in theology because the religious tradition has tended strongly towards seeing pure spiritual life as a higher form of life than embodiment - perhaps because the spirit was unconfined, incorruptible, and apparently lacked the multiple constraints of boundedness that a body seems to imply.
However, the Christian fact of the divine Jesus becoming incarnate, dying and then being resurrected in a perfected but human body - strongly implies that incarnation is a higher state than immaterial spirit life.
Yet the fact of incarnation and resurrection has been, for most of Christian history, confused by the dogmatic assertion that God the Father was disembodied, an immaterial spirit - despite multiple scriptural references which seem to imply the opposite. An anti-body bias, an equation of the body with sin and limitation, was not merely confined to the Gnostics, but has been a constant temptation and lapse among mainstream Christians.
Christianity has been confused and inconsistent on this subject of incarnation
through most of its history; and often lapsed into talking about the
body as corruption and the spirit as higher and purer and more divine. Consequently, mortal incarnate life was often perceived as intrinsically second rate or actually pointless, compared with spiritual life in Heaven. Many Christians craved the release from suffering and potential for absorption into the divine offered by the discarnate, spiritual state (and 'Eastern religions' throughout continued to regard pure spirit as a higher spiritual state than incarnation).
By clearly stating that God the Father has a body, of the same nature as the resurrected Christ, of the same nature as Men, then this historic confusion was transcended.
Having a body is potentially better, a higher state, than not having a body - with greater potential for power in general and for creation in particular. The history of a human soul begins with pure spirit, and ascends to incarnation. The history of life into consciousness can be seen as a process of 'condensation'.
So, why is incarnation a higher state than pure spirit? Why is it a spiritual progression to 'get a body'?
In the first place it needs to be recognised that when we are incarnate, it is not a matter of the body 'clothing' the spirit - rather, the two become one: an irrevocably (when the body and spirit are spilt apart at death this is not a restoration of the spirit life, but a maiming of the spirit. Resurrection reunite the severed body and spirit, enabling the purification of both).
Indeed, it is not incarnation if we imagine that the spirit merely inhabits and controls a body - as if it was inside a diving suit, or a 'mech' suit - this is a spirit being creating the illusion of a body, a projection of a body - this would be a spirit merely manipulating the material world but not inhabiting it.
What happens with incarnation is that the immaterial spirit comes to inhabit the material world. The soul thereby attains the fullest possible integration with the whole of reality.
(Note - I am using a omenclature here where the soul is our eternal personal self; the spirit is the first and immaterial form which the soul attains. The immaterial is contrasted with the material - in terms not so much of nature as of properties such as detectability, measurablility, confinability. The incarnate soul includes both spirit and body in fusion.)
Consider: assuming the spirit is immaterial, then as a pure spirit the human soul is excluded from the material form of reality.
By incarnating, the soul attains the fullness of integration with reality: material as well as immaterial.
The discarnate soul of pure spirit lacks a full sense of itself from-which to work - it lack boundaries, and therefore cannot be fully free. Freedom is the basis of creativity, and freedom must have a discrete origin. Hence incarnation.
Incarnation is more a matter of concentration than of constraint - and enhanced creative power is a product of that greater concentration and of fuller self-awareness, which is characteristic of the incarnate soul.