Proto-Indo-Iranian religion is the religion followed by the people who spoke Proto-Indo-Iranian language, thousands of years ago. They believed in many gods and goddesses who had different powers and responsibilities. They believed that these gods controlled everything in the world and could give them things like good crops, healthy animals, and even victory in wars.
They also believed in the concept of sacrifice, which meant giving something valuable to the gods as an offering. They would offer things like food, animals, and even precious metals like gold and silver to show their respect and allegiance.
The religion was also influenced by the seasons and nature. They believed that certain gods controlled the sun, moon, wind, and rain, and by worshiping them, they could have good weather, fertile land, and healthy livestock.
Different groups of people could worship different gods and have different beliefs, so their religion was not the same everywhere. As time passed and different cultures emerged, the religion evolved and changed, giving way to new beliefs and gods.
In summary, proto-Indo-Iranian religion was the ancient religion followed by the people who spoke Proto-Indo-Iranian language. They believed in many gods and goddesses, sacrifice, and the influence of nature on their lives, but the religion varied by region and evolved over time.