Based on the provided sources, it can be asserted that the fear of the unknown and chaos indeed played an important role in the emergence of religious beliefs.

From Fear to Faith: The Complex Genesis of Religion

Based on the provided sources, it can be asserted that the fear of the unknown and chaos indeed played an important role in the emergence of religious beliefs. However, reducing the entire origin of religion solely to a product of fear would be an oversimplification. Instead, religion served as a way to confront the most ancient and overwhelming fears, allowing a person to find protection and hope in the face of terror from unknown forces.

As one of the sources notes, religious ideas emerged as a response to the inner state of primitive man:
"Magic is not only about acquiring power and battling dangers and the fears they evoke, but it is also a source of fears and dangers. Humans fear magical forces and seek protection from them first in religion, then in science. ... Religion is the struggle against this terror anticus and liberation from it." (source: link txt)

Another text emphasizes that fear in primitive consciousness repeatedly manifested itself and led to the search for support through various spiritual practices:
"In experiencing intense fear, a person usually forgets any sense of grandeur and is inclined to dwell in low places, as long as he is freed from the anticipated dangers... Ancient primitive humanity was obsessed with fear, terror anticus, a fear of chaos and unknown forces of nature..." (source: link txt)

Additionally, an important factor in the formation of religions was precisely the desire to free oneself from an overwhelming sense of fear:
"But if it is said of religion itself that its gods were born out of fear, then one can hardly argue against this, for nowhere did people flee from their gods, as they run away from that which causes fear. On the contrary, it was precisely in the face of circumstances that engender fear... that they approached their gods with exceptional devotion and trust." (source: link txt)

Thus, it can be concluded that while the primordial fear of the unknown, chaos, and natural phenomena became a catalyst for the formation of a religious mentality, religion as a subculture encompassed much more complex elements. These elements involved not only attempting to systematize and control fear by creating a system of beliefs and taboos, but also the pursuit of protection, moral guidance, and explanations for the meaning of existence. In other words, besides the emotional reaction to the unknown, significant social, cultural, and philosophical needs of ancient humanity played a crucial role in the formation of religious systems.

Supporting citation(s):
"Magic is not only about acquiring power and battling dangers and the fears they evoke, but it is also a source of fears and dangers. Humans fear magical forces and seek protection from them first in religion, then in science. ... Religion is the struggle against this terror anticus and liberation from it." (source: link txt)

"In experiencing intense fear, a person usually forgets any sense of grandeur and is inclined to dwell in low places, as long as he is freed from the anticipated dangers... Ancient primitive humanity was obsessed with fear, terror anticus, a fear of chaos and unknown forces of nature..." (source: link txt)

"But if it is said of religion itself that its gods were born out of fear, then one can hardly argue against this, for nowhere did people flee from their gods, as they run away from that which causes fear. On the contrary, it was precisely in the face of circumstances that engender fear... that they approached their gods with exceptional devotion and trust." (source: link txt)