Brahman as per Bhagavad Gita is one and only one, the creator of entire cosmos.
Brahman is the absolute reality of life can nothing other than Brahman existed in cosmos.
Lord Brahma, Lord Vishnu and Lord Shiva were attributes of Brahman having nothing to do with absolute reality. In real life none by the name of Brahma, Vishnu or Shiva existed in world.
Lord Krishna in Bhagavad Gita says all worship; prayers must be directly addressed to Brahman and never its attributes, hordes of gods and goddesses in Hinduism.
We human beings exist because souls’ atmans exist and souls’ atmans exist as Brahman exists.
The entire cosmos could not be real, exists only in thoughts of God Almighty, like image in the mirror.
The present cosmos created when Brahman (God Almighty) exploded self with a big bang.
The sum total of all souls’ atmans in cosmos in their purity state is what we defined as Brahman.
We as a soul atman, the spirit within were miniscule part of Brahman, essence being the same.
Lord Krishna in Bhagavad Gita says Hinduism is monotheistic having Brahman as its God. Spiritual people believed in Nirakaar (having no form), Nirguna (without attributes) form of Brahman. Religious people believed in Sakaar (having a form), Saguna (having attributes) form of Brahman.
It is beyond human intellect to conceptualize the primordial cosmic energy we called Brahman.
Brahman can be realized only by indulgence in spirituality never path of religion (rituals).
One can have a communion with Brahman on one-to-one basis only after gaining enlightenment.
Journey to and fro from Brahman and back entails a cosmic sojourn of maximum 8.4 million bodies in insect, plant, animal and finally human form.
The ultimate goal of life for all human beings on mother earth is reaching Brahman.
As a human form we were intimately connected to Brahman, for the reason that it was only in human form the soul atman within finally liberates self from cycle of birth and death forever, regaining its lost original pure prime pristine primordial form.
Indulging in spirituality Hinduism anyone world over could easily reach Brahman. To reach Brahman one needs becoming a Swami Vivekananda in real life.
The 700 shlokas verses contained in Bhagavad Gita eulogize merits of indulging in spirituality to reach Brahman in our lifetime.
There was nothing more pious, more pure than indulging in Bhagavad Gita to reach cosmic end of life, Brahman.