For non-Christian monotheists, the gulf between God the Creator and Man - numbered among His creations - is qualitative: there is a difference in kind.
On the one hand there is God the creator; and on the other hand there is everything-else - that which He created.
But for Christians things are not so straightforward. For Christians there is the example of Christ being both God and Man - and the clear implication that there is therefore a continuum between God and Man.
This implies that the gulf between God and Man is quantitative, rather than qualitative (accepting that truly vast quantitative differences are, for almost all practical purposes, qualitative 'in effect'.)
For Christians there is also the statement, the promise, that Man can be deified; that Men can become a Sons of God - and this again implies a quantitative continuum between God and Man.
Therefore, for Christians there is ample evidence that God and Man are of the same kind, and although there is yet a truly vast quantitative gulf between - yet there is the promise and hope that this gulf can be bridged (by means of the God-Man Christ).
The problem for Christians is therefore to understand how this (truly vast) quantitative gulf may be bridged: what kind of process could explain this?
The two main ideas about how the gulf between God and man may be closed are:
1. An evolutionary spiritual progression of Man towards God spread across vast time-scales of both pre-existence, and a post-mortal life. (i.e. The Mormon solution.)
2. An evolutionary spiritual progression of Man towards God spread across mega-multiple cycles of reincarnation. (The Hindu solution, also other Far Eastern regions - and one incorporated into various modern spiritual movements such as Anthroposophy, some New Age writers, and also William Arkle.)
My point is that an acceptance of the (Christian) principle of deification and an acceptance of the centrality of spiritual progression, theosis, sanctification etc in Christian life; will, in combination, lead on to a need for explanations that:
1. Extend beyond mortal life, and
2. Extend across extremely large time-scales
...in order to make comprehensible how a Man may become a god.