Final answer:
Mr. Brown likely disapproves of the Ibo's religion due to its polytheistic nature, which goes against his own monotheistic beliefs.
Step-by-step explanation:
Mr. Brown does not like the Ibo's religion primarily because they practice polytheism, featuring sacrifices to a pantheon of smaller gods rather than exclusively worshiping a singular, main god, which clashes with his own monotheistic beliefs. In Things Fall Apart, Achebe illustrates the cultural conflict between the Igbo society and Christian colonizers. The Igbo religion includes a complex system of gods and ancestral spirits, with Chukwu often regarded as the supreme god.
However, the presence of many lesser deities and the role of spirits and ancestors in religious and community matters stand at odds with the monotheistic, exclusive worship demanded by Christianity, as represented by Mr. Brown. The Igbo societal structure, characterized by a diversity of autonomous villages and polytheism, is essential to understanding the tension with colonizers like Mr. Brown, who promote a single-god worldview, derived from Biblical scriptures like Exodus which emphasize a jealous God intolerant of idol worship. Furthermore, the Igbo's connection with nonhuman elements like nature, animals, and ancestral masks such as the egwugwu embody a spiritual tradition that diverges sharply from Christian beliefs.