Relation between ourselves and God
To help your understanding of the relation between the individual Self or individual Consciousness and God, i.e., the Universal Consciousness, I will use the well-known example of the ocean and the waves. The wave is a part and an expression of the totality called the ocean. However, the essential nature of the wave and the ocean is water (H2O). Although the ocean is immense and the wave is a very small part of the ocean, both share the same nature, i.e., they are both water (H2O).
Similarly, each human being as a body-mind entity is an infinitesimal part and expression of the universe. However, its essential nature and that of the whole universe is the same, Consciousness. Consciousness concerning the whole Cosmos is called God (Brahman, Spirit, Tao, etc.) and concerning each person is called true Self (Atman, essence, Soul, etc.). That is, the universal Consciousness (God, Brahman) when expressed through man is called individual Consciousness or the true Self (Atman in Sanskrit). Moreover, Consciousness, unlike water, is formless and spaceless, that is why there is no difference in quality and quantity, i.e., there is no such thing as a big or small, superior or inferior Consciousness.
The Consciousness in us is God Himself but due to the limitations of the mind it appears as the seemingly individual Consciousness. However, when our mind is freed from all limitations we realize that we are God Himself.