Acts 17:28a - God Is The Source Of Our Very Existence.

For in Him we live, and move, and have our being; Acts 17:28a

[For in him we live] The expression "in him" evidently means by
him; by his originally forming us, and continually sustaining us. No
words can better express our constant dependence on God. He is the
original fountain of life, and he upholds us each moment.
[And move] It means that we derive strength to move from him; an
expression denoting "constant and absolute dependence." There is no idea of
dependence more striking than that we owe to him the ability to perform the
slightest motion.
[And have our being] This denotes that our "continued existence"
is owing to Him. That we live at all is his gift; that we have
power to move is his gift; and our continued and prolonged existence
is his gift also. Thus, Paul traces our dependence on him from the
lowest pulsation of life to the highest powers of action and of
continued existence. It would be impossible to express in more emphatic
language our entire dependence On God. (Barnes' Notes)

God is the living and immanent principle of all existence.
[Jamieson, Fausset, And Brown Commentary]

The mighty power that works through all nature and sustains all
things is not, as some men of science claim, merely an all-pervading
principle, an actuating energy.  God is a spirit; yet He is a personal
being, for man was made in His image. ED131,2

God is known in his creation, and he is close to every one of
us. But he is not trapped in his creation--he is transcendent. God
is the Creator, not the creation. This means that God is sovereign
and in control, while at the same time he is close and personal. Let
the Creator of the universe rule your life. [Life Application SB]

God has made man in such a way that instinctively he longs for
God [Barclay Commentary]

Since God is the creator of men, he must at least be greater
than men. Therefore to identify the Deity with something man has made
or imagined is the height of folly and the depth of sin. [Wycliffe
Bible Commentary]

God is not the made but the maker; and he who made all things
cannot be worshipped by anything made by the hands of man. It is all
too true that men often worship what their hands have made. If a
man's God be that to which he gives all his time, thought and energy,
many are clearly engaged in worshipping man-made things. [Barclay

If this verse is true, and it most certainly is, why do we so
often disregard God?  Do we treat Him with a token quiet time some
days?  Do we run to Him in a crisis and ignore Him when things are
running smoothly?  What we need to understand is that God created the
earth with His Word; He determines the times and places of each
person's life;  He knows the number of hairs on our head;  He ordained
the number of days of each life and wrote them in His book.  What
would/could the Christian life be like if we were able to live in a
continuous attitude of prayer with God; if we continuously acknowledged His
presence; if we remained in an on-going posture of listening for His
voice.  Be thankful that each day brings new beginning.  Today we have
the opportunity to start over and make Jesus top priority!  Let's do
it! [In His Time; Walk With Wisdom]

Since in him and upon him we live, we ought to live to him;
since in him we move, we ought to move towards him; and since in him
we have our being, and from him we receive all the supports and
comforts of our being, we ought to consecrate our being to him, and to
apply to him for a new being, a better being, an eternal well-being.
(Matthew Henry's Commentary)

"The holy blessed God never does evil to any man. He only
withdraws his gracious presence from him, and then he necessarily
perisheth." (Adam Clarke Commentary)

The hand that sustains the worlds in space, the hand that holds
in their orderly arrangement and tireless activity all things
throughout the universe of God, is the hand that was nailed to the cross
for us. ED131,2