God is present everywhere at all times. If you have a string you will have to admit that God is in the string as well. If you cut the string into two halves, you will have to say that the whole of God exists in each half of the string. You cannot say only half of God will exist in each half of the string.
If you cut the string further into many small parts, you will again have to say that God exists in his fullness in each and every part of the string. You cannot say that only little parts of God exist in the parts of the string. When you finally divide the string into little atoms you will have to admit that God is present in each atom. And finally when you cause even the atom to vanish–God will exist even where there in nothingness. You cannot divide God into parts, you have to admit that the whole of God exists at each and every point in space and time.
One can imagine a man sitting in a television studio. His picture is being broadcast all over the world. Wherever there is a television set, his picture will appear on the screen. This is an example of omnipresence–being present at all places simultaneously. The entire picture of the man appears at each and every point of space. All that is needed is a television set to behold it. In a like manner God exists at each and every point in space and time in His fullness. He is revealed in the pure heart of a devotee.
God is also defined as an infinite circle whose centre is everywhere and whose circumference is nowhere. Thus at each and every point in space and time there is the whole of the Infinite God.
Suffice it to say that it is not necessary to understand God through the intellect, which is very limited in any case. If the sun has come out in the sky it is better if we use its light to do our daily tasks in, rather than argue about why and how it came.
The human form of the Avatar of God upon earth is like the ray of light that comes from the Sun and reveals the Sun to the human eye. If the entire Sun were to come down it would burn everything. For limited human beings God must assume a limited human form, which they can understand and identify with.
There are some very good and pure souls upon earth who also reflect the light of God. To understand this, think of the rays of the sun falling upon little particles of dust. If there be a particle of glass amongst the particles of dust, it will immediately reflect the light of the sun. These are the pure souls about whom it has been said: “Blessed are the pure in heart for they shall see God.”