Now, having said all that, I think we can safely say this much is true---there was something uncaused and self-existent at the very beginning ... before there was even space and time. We can call it self-existent being, and it is still 'here.' It is still a case of---it is. It exists, not from itself, but of itself. And this pure actuality of existence or being-ness, having within it the plenitude of all being as well as all activity, is the undivided and indivisible wholeness of all existence. The what is is forever becoming the what will be, forever releasing and so realizing its innate creativeness. This being-ness---as well as becoming-ness---fills all time and space with its presence, hence the Biblical concept of omnipresence.
Omnipresence. What a wonderful word! We are talking about an ‘all-encompassing’ uncreated reality ('Presence')---reality in self-expression, if you like---that, although unmanifest, forever takes shape and form as manifest existence and being-ness. Omnipresence means ... there is. That's it! There is. That's all of reality. That's all of life. The past? Well, the past is 'there is ... no more.' And the future? The future is 'there is ... not yet.' We are talking about a reality that is truly limitless, encompassing all things including all of space---and yet beyond all space as well. This Presence is not ‘transcendent’ in the sense of some supposed anthropomorphic deity in the ‘upper regions,’ nor can it be said to be immanent for the Presence is not actually contained ‘in’ or ‘within’ anything, nor can this Presence be said to be in any way ‘separate’ from the universe (that is, the sum total of all that is) for the notion of separateness denotes divisibility whereas this Presence is essentially indivisible. It is not only present everywhere, it is Presence itself … everywhere! You can call it the ‘spirit of life’ if you wish. It is to be found everywhere, but especially at the very centre of your being.
The words 'I AM' refer to the subject---note that word, 'subject,' not object---of all existence. The Bible says that I AM is God. So, God, that is, the very essence and being-ness of life itself, becomes what God has said that which God is---'I AM THAT I AM.' We are talking about the very presence and power of life itself---there is only one such presence and power---which forever gives of itself to itself in order to perpetuate itself ... and to become. In a deeper sense, we are talking about the Self-knowingness of God, for we too can be conscious (or rather self-conscious) of that very same I AM presence and power that is the ground of our being, indeed, the ground of all Be-ing. It is the All-in-all.
So, HaMakom is the life that is the subject of true existence, the very life that lies within, and otherwise manifests itself through and as objects, being all persons and things---the very livingness, or rather Self-livingness, of life itself. Put simply, perhaps even too simply, each of us is I AM in expression---as you and me. Yes, each of us is an 'eachness' within the ALL-ness of the Divine.