There is a common metaphysical assumption (and described mystical or intuitive experience) of an original state of oneness.
I would distinguish between the subjective experience of being immersed in one sea of consciousness, each mind essentially passive; with minds open to one another to make a single pooled mind... The only agency being (to various degrees) an awareness that this is the situation...
And on the other hand that this unity of "will" is only that of passivity and incapacity, and does Not result from individuals sharing in God's creative purposes.
Because each mind is part (and "always" has been) part of an individual being. This being has some potential to develop individual agency, but this entails becoming cut off from passive immersion in the group mind... becoming Free. Such freedom is necessary if an individual being is to contribute something from-himself, original, new... to ongoing divine creation.
Thus here we are!
There was indeed a primal oneness of subjective experience, but there was and is a primal multiplicity of beings - thus multiplicity of 'interests', goals, selfishnesses...
God's"problem " was/ is to develop the creative agency of the many beings.
It would be futile to return to primal passivity, therefore Men must choose to *enlist" in God's creative-project... To bring each his own creative free agency to the expansion of creation.
Therefore we do not seek oneness, but harmonious multiplicity.