Q: How to fathom “God within everyone”?
A: Degrees of Grace.
From:
ewtn.com/library/DOCTRINE/MNGGRACE.HTM
…The divine presence envelops and penetrates all creatures. It is a knowing presence, which pierces the secrets of hearts; a powerful presence, which gives beings their activity,
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the power to ‘be’ what it is. These are the three aspects of his presence in creation. It is intimate to creatures. Strictly speaking, God is more present to things than they are to themselves. ‘God who art in my heaven more my heaven than heaven,’ said Pere Chardon; he is in me more me than myself. And if for one instant he were to forget the world, it would fall immediately into nothingness.
Yet God who is so mysteriously present to the world is not immersed in the world; he is not dissolved in things. He keeps his absolute transcendence. If, then, he fills all things, it is as the infinite Cause of an effect that is imperfect and limited: ‘Do not I fill heaven and earth?’ (Jer. xxiii. 24), he asks, and the psalmist says, ‘If I ascend into heaven, thou art there; if I descend into hell, thou art present’ (Ps. cxxxviii. 8).
**There is a second act of God that is still more overwhelming. It is a little like the act of a mother who feels the child she has brought into the world is too remote, and takes and presses him to her heart. God unites himself in a new way to the souls who open themselves to his grace and his love. This is a presence still more mysterious, more hidden, the presence of indwelling. **
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That God desires thus to come down secretly into our universe to find his dwelling in it is a truth already perceived dimly in the Old Testament. But the fullness of this revelation is to be found in the New Testament. Consider, for example, the opening verses of chapter xxi of the Apocalypse: ‘I, John, saw the holy city, the new Jerusalem, coming down out of heaven from God. . . .And I heard a great voice from the throne, saying: Behold the tabernacle of God with men; and he will dwell with them. And they shall be his people, and God himself with them shall be their God. And God shall wipe away all tears from their eyes, and death shall be no more. Nor mourning, nor crying, nor sorrow shall be any more; for the former things are passed away.’
In this second way, God cannot dwell in material things; but where there is a spirit, he is able to come down and hold converse with that spirit. And this presence of indwelling is conditioned by the descent, in that spirit, of grace in its fullest meaning. You see the importance of grace: it transforms the soul and fits it for the immediate indwelling of the divine Persons.
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We must now observe that God’s love is of two kinds:
(a) a love which St. Thomas calls common, by which God loves the blade of grass, the star, the pebble of which the film “La Strada” speaks… All these beings are, and they are by an act of divine love and volition. Even the sinner has his being, even the devil, and this being would not subsist did not God continue to will it. What is evil in the devil is his perverted will, the act by which he annuls the love offered to him; but his being itself is a richness; being is always a splendour, a participation in the divine Source. In this sense we can say that the common love of God extends to all that exists, in so far as it exists;
(b) a special love by which God elevates the rational creature above the conditions of his nature, clothes him as if with a new nature, brings him into a new universe. He makes him a sharer in the divine life by pouring into him created grace. Created grace is a reality, a quality, a light that enables the soul to receive worthily the indwelling of the three divine Persons.
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God could have created a universe composed solely of natures, but in this hypothesis what would have been our relations with God? We should know the world by reason and from the world we should ascend to God as to its source. We would know God only through a glass, darkly. What we would see first would be the universe, its riches, its beauty, its being, and doubtless that is something!
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It is borrowed being, dependent on the Being per se, the Absolute. Then, in the order of natures, we would know God as the great X on whom the world depends. He would be the Master, the Creator, but we could not enter into a relationship with him as friend to friend. Aristotle said we cannot speak of friendship with the immortal gods, because friendship supposes a certain equality.
But God does not leave us in that condition. He comes out to meet us, and his desire is to set up in us a new universe of life, light and love, so that we may be able to make our way towards the depth of his being and intimacy with him, to speak to him as our friend. That is the mystery of the elevation of our nature by grace, and that is why we call this new life supernatural. It transforms, imbues our whole being to make it proportionate to an end hitherto unknown to it, one which goes beyond our nature. God raises us up, rather as the artist uses an instrument to make it produce what by itself it would be incapable of—joy, sadness, prayer. Something beyond its own power acts through the instrument: it is a human heart that touches the instrument and the effect produced, being on the plane of its cause, is a human effect. If divine grace comes down into me, I shall no longer be in community only with the things of earth and with men, but with the divine Persons, with all that is deepest and most hidden in the heart of God.