राम वही जो रमता सकल जहान
Above Hindi line meaning is that "God is omnipresent and is in every atom of this Universe". But how God is there everywhere in the Universe?
Meaning of omnipresent is that one who is present everywhere. God is one who in it's un-manifest, unseen, subtle aspect is always present all around us. This omnipresent God is one who is full of knowledge & knows everything about this whole world & also knows about all the people of this world. Just like all this world look infinite so God is present in every inch of the space. Every nook & corner of this Universe is filled by Him. He is therefore called Brahm (God) who is Truth Absolute, Knowledge Absolute and is Infinite.
Now just see below verse of Bhagwat Gita:
vayuh sarvatra-go mahan
tatha sarvani bhutani
mat-sthanity upadharaya" (Bhagwat Gita: Chapter Nine verse 6)
"Sri Krishna said: Understand that as the mighty wind, blowing everywhere, rests always in the sky, so do all created beings rest in Me."
The meaning of above verse is that just like wind blowing everywhere always exists in space and both can't be seen by our eyes, similarly whole world exists in all pervasive, God, Brahmn which exists just below this space. Whole material Universe exists within that Brahmn called God.
Below are some more verses from Bhagwat Gita which explains all pervading God in this Universe.
"maya tatam idam sarvam
na chaham tesv avasthitah" (Bhagwat Gita: Chapter Nine verse 4)
"Sri Krishna said: By Me, in My unmanifested form, this entire universe is pervaded. All beings are in Me, but I am not in them."
"prakritim svam avastabhya
visrijami punah punah
bhuta-gramam imam krtsnam
avasam prakriter vasat" (Bhagwat Gita: Chapter Nine verse 8)
"Sri Krishna said: The whole cosmic order is under Me. Under My will it is automatically manifested again and again, and under My will it is annihilated at the end."
God is called Brahmn,
Whole world dwells in Brahmn,
Whole world comes from Brahmn,
Whole world goes back in Brahmn,
Whole world breathes in Brahmn,
Let's worship that Brahmn, the God