Why did the Romans steals Egyptians religion?

There was no such thing as "stealing" deities in ancient polytheisms. But a religion could be influenced by another, and integrate one of his divinities: e. g., during the New Kingdom, when Egypt had diplomatic exchanges with the Hittites, the Hittite goddess Ishtar entered the Egyptian pantheon. read more

They didn't. The Ancient Roman religion was most similar to that of the Ancient Greeks. The Ancient Greek religion, in turn, may have borrowed slightly from the even more Ancient Sumerians, but the Romans most certainly didn't steal the religion of the Egyptians. Any similarities are likely because the Egyptians also borrowed a bit from the Sumerians. read more

Some people like to say that the Romans did, in fact, copy other deities – but then so did the Greeks. And every other culture since the days of the single, Indo-European culture and religion of waaaaaaay back when. read more

The Egyptians based their religion off of the Nile River because it was the source of life for that area. The sun god, Ra, for example was believed to cross the river of the underworld upon a boat which is why there was day and night. read more

As the empire expanded across the Balkans, Asia Minor and into Egypt, Roman religion absorbed many of the gods and cults of conquered nations, but the primary influence would always remain Greece. With only a few exceptions, most of the Roman gods had their Greek counterparts. read more