Of course religion is connected to tribalism.

[MineralMan]

7. Early tribal humans feared pretty much everything.

It was dangerous being a human. The tribes developed because of fear, since individual humans don't survive well.

The chieftains, generally, also employed fear to create their power over the tribe. Violating the chieftain's rules was generally punishable by death. So, the security of the tribe was tempered by the fear of the chieftain, in most cases. The simple answer was to follow the rules so you had the protection of the tribe.

The story-teller's job was to moderate the fear of the tribe, though stories that explained things and the reasons for things. We are calmed often by stories that help us to understand. Why did Barm die yesterday after being ill? The story-teller knows and will explain it to you. An evil spirit within him was the cause, in most cases. If you do the things the story-teller tells you to do, and obey the chieftain, though, you may escape Barm's fate.

Fear was a constant in early human tribes. Exploiting that fear and helping allay it is the path to power for the chieftain and the story-teller, who soon also became the shaman, who had rituals designed to allay fears.

The Chieftain is a strong person. The story-teller is a smart person. Between the two, the success of the tribe is possible. Reading anthropological writings will let you see that story again and again. There is always a Chieftain and a story-teller or shaman.