For the Brahmo Samaj, monotheism meant an unwavering affirmation of a single, supreme Reality that is formless, eternal, and all-pervading. This one God was not to be approached through images, idols, or anthropomorphic depictions, but as a transcendent, attributeless Brahman beyond all physical representation. Traditional polytheistic worship and the veneration of multiple deities were set aside, with such deities understood, at most, as symbolic rather than literally distinct divine beings. The movement also rejected the notion of divine incarnations, maintaining that the supreme Reality does not assume bodily form.

This monotheistic vision was closely tied to reason, conscience, and direct spiritual experience. God was regarded as knowable not merely through inherited scriptures or ritual authority, but through the disciplined use of rational reflection, inner moral awareness, and contemplative insight. In this way, monotheism was not a dogma imposed from outside, but a truth to be realized inwardly, without dependence on priestly mediation or elaborate ceremonies. Worship thus centered on prayer, meditation, and devotional expression directed solely to the one supreme Being.

The Brahmo understanding of the one God also carried a distinctly universalist character. God was seen as the universal father of all humanity, not the exclusive possession of any single community or tradition. This universal God was understood to transcend sectarian boundaries and to be equally related to all peoples and religions. Such a view fostered an inclusive spiritual outlook, in which the essence of true religion lay in a shared relation to the same ultimate Reality rather than in competing claims of superiority.

Finally, monotheism in this context was inseparable from ethics. To affirm one formless, omnipresent God was to commit to moral integrity, social responsibility, and inner purification. True worship was expressed less in ritual observance and more in righteous conduct and service to others. The Brahmo Samaj thus interpreted belief in one God as both a metaphysical conviction and a practical call to live in accordance with truth, justice, and compassion.