Despite a constant 'gnostic' or 'Platonic' tendency among intellectuals to ignore or denigrate the body and emphasize and valorize the spirit or soul - the body is absolutely central and essential to Christianity; in the sense that one big innovation was resurrection: the promise of another life after death but not merely a soul-survival but another life in a body.
But why? What is the body for - in a Christian theological sense: what is the function of the body?
In a nutshell: why is it (for Christians) better to have a body, than not to have a body?
Because if it was better not to have a body, then we would not be resurrected - but only the mind/ spirit/ soul would survive death.
Indeed, more than this, there must be a very big advantage indeed to having a body - considering all the trouble it causes.
But what is that advantage?
The idea that I wish to suggest here is that the body protects the soul.
Specifically, the body protects the soul from direct spiritual interference and influence by evil spirits.
This means that evil spirits (I mean Satan and his minions) can only get-at the soul indirectly, via the body - e.g. via enticing or tormenting the body - because the soul is protected in the body.
This sets up a situation in mortal life whereby evil can only 'get in' by being invited or allowed in. The default situation is that evil cannot get in. Because the body is protecting us, we have to actively open the door and ask evil to enter - give evil access.
The contrasting situation could be seen during sleep if we suppose that dreams are happening 'in the spiritual realm', that our spirits become loosened from our bodies, and that in dreams we live as (almost, but not quite) 'naked souls' and experience (re-experience) living without our bodies.
But living as spirits this time not in Heaven and a good and loving environment but on earth and in mortal life, and among the fallen angels...
In dreams (specifically nightmares) there is perhaps a taste of what life would feel like if evil had a much more direct access to our souls; evil spirits attacking our selves, putting-in ideas and emotions, shaping the process and direction of our thinking etc.
Being awake and in a body we are protected from this.
So, there is a sense in which the body enables us better to withstand and resist an evil environment - which is another way of talking about being more of a developed self, more responsible, more autonomous, more of a free agent.
In other words, getting a body and having a body is a forward step in theosis or spiritual progression.
The body is what enables us potentially to withstand the problems of mortal life, in this extremely difficult environment of mortal life; with its great opportunities for learning and development - but commensurately great spiritual hazards.