gimme 1 sentence about how ancient rome and ancient greek shared the same religon

Ancient Rome and Ancient Greece shared a polytheistic religion, with many of the same gods and goddesses being worshipped in both civilizations.

write it like a 4th grader

Both Ancient Rome and Ancient Greece worshipped lots of gods and goddesses, and they believed in many of the same ones.

whats that religon called

It's called polytheism, which means believing in many gods and goddesses.