If people have believed false Gods propagated by religion over millions of years, the length of time does not prove it is God in truth.
God in truth is hidden by the universe because the universe is merely an illusion created out of God. God is in the form of Athma.
Brihadaranyaka Upanishad: ~ Brahman (God in truth) is the form of the Athma, and it is indeed Athma itself.
Rig Veda: ~ The Atman is the cause; Atman is the support of all that exists in this universe. May ye never turn away from the Atman, the Self. May ye never accept another God in place of the Atman nor worship other than the Atman?" (10:48, 5)
How can you worship God? That implies two ~ the worshiper and the worshiped, whereas the God is non-dual. One can worship his idea of God only or realize his unity with it when he can’t worship it as a part.
When Upanishads and Vedas declare that, “God is the form of the Athma, and God is indeed Athma itself” then why accept another God in place of the Atman or worship other than the Atman.
People, who worship the belief-based God, are hallucinating that they become one with such God. Veda and Upanishads condemn worshiping God other than Athma.
Brihadaranyaka Upanishad says: ~ "He who worships the deities as entities entirely separate from him does not know the truth. For the Gods, he is like a pasu (beast)". (1. 4. 10)
Even Bhagavad Gita says: ~ “Brahmano hi pratisthaham Brahman (God in truth) is considered the all-pervading consciousness which is the basis of all the animate and inanimate entities and material (Gita 14.27)
When Bhagavad Gita says, God is considered the all-pervading consciousness which is the basis of all the animate and inanimate entities and material then nothing has to be accepted as God other than consciousness.
Bhagavad Gita Chapter: ~ “All those whose intelligence has been stolen by material desires, they worship many Gods. (7- Verse)
Vedas, Upanishad, and Bhagavad Gita Bible confirm the Soul, the Self, which is present in the form of the Spirit or consciousness is God in truth. :~Santthosh Kumaar