एको देवः सर्वभूतेषु गूढः सर्वव्यापी सर्वभूतान्तरात्मा ।
कर्माध्यक्षः सर्वभूताधिवासः साक्षी चेता केवलो निर्गुणश्च ॥
साक्षी चेता केवलो निर्गुणश्च ॥

(श्वेताश्वतर  उपनिषद् ६:११)

God, who is one only, is hidden in all beings;  He is all-pervading, and is the inner self of all creatures.  He presides over all actions, and all beings reside in Him.  He is the witness, and He is the Pure Consciousness, free from three gunas of Nature.

Svetaashvatara Upanishad 6:11