Seekers indulging in spirituality always believed in Nirguna form of Brahman (having no form). For a spiritual traveler Brahman (God Almighty) existing in our heart in miniscule form as soul atman. As a logical seeker of god one could never belie existence of soul atman in our heart.
A believer of Nirguna Brahman never went to a temple, church or mosque to pray to god. When God Almighty existed in our heart, what was the use of going to religious congregations!
As detailed in Bhagavad Gita, Brahman always is Nirguna (without an attribute) and also Nirakaar (having no form). As also proved by science, even after best efforts scientists’ world over have not been able to recognize presence of soul atman inside our heart.
Brahman (God Almighty) cannot be seen, it can only be realized by travelling path of spirituality. Similar as we can detect presence of a flower by its fragrance, we can also detect presence of God, Brahman in day-to-day affairs of life.
If we go by doctrine of Maya (veil of illusion) propagated by Adi Shankaracharya we shall find that other than God Almighty, Brahman nothing existed in cosmos. If we say the present cosmos has a boundary then what beyond. If the present cosmos was without a boundary as per Adi Shankaracharya it could exist only in thoughts of God Almighty.
The manifest cosmos came into being when the Nirguna Brahman exploded self with a big bang. From beginning of time Brahman is Nirguna and shall continue to be.
Spirituality does not believe in existence of attributes of God like Lord Brahma, Lord Vishnu and Lord Shiva. Spirituality as detailed in Bhagavad Gita clearly says Brahman is one without a second. In reality no gods and goddesses existed in entire cosmos. Lord Krishna in Bhagavad Gita says even if one prays to various gods and goddesses, all prayers get directed to Brahman.
Truly Brahman was the only truth of life existing in cosmos. Broken down to basic building block of cosmos the whole cosmos is made up of clusters of atoms and molecules. Even the human form is nothing but a gaseous formation, clusters of atoms and molecules. Only when perceived from senses point of view things appeared solid, in reality all was gaseous formation.
If everything was gaseous formation how could Brahman be Saguna (having a form)!