”That same Lord who is one and unique is concealed in the hearts of all the living entities. Although He is all-pervasive, He guides every living entity from within as their Supersoul. He rewards everyone for their performed karmas. He is the only shelter for all and witnesses every action performed. He is fully active, completely pure and is beyond the three modes of material nature.”

eko devah sarva-bhutesu gudhah
sarva-vyapi sarva-bhutantar-atma
karmadhyaksah sarva-bhutadhivasah
saksi ceta kevalo nirgunas ca

PURPORT BY SRI KRSNA BALARAM SWAMIJI

This verse proves how the Supreme Lord is unlimited. He is not limited to only being all-pervading, He is localized in the heart as Paramatma as well. Many people limit Him to being impersonal and having no physical features but He is not limited to anything because He has His personal form as well. He witnesses everything because He is seated in the heart. Therefore even if something is done secretly He sees it. He is always active because even if a living entity falls asleep He remains active because the soul is still conscious while asleep. He is beyond the three modes of goodness, passion and ignorance and until one rises above these three modes they cannot perceive Him.

[Svetasvatara Upanisad, 6.11, KBS0094]