What happened to a person who didn't worship gods in ancient Rome?

Answer 1

Nothing. The great social pressure to belong to a religion that is a mark of today's Muslim faith and of the Christian faith until some 60 years ago, did not exist in ancient Rome. There was a great number of religions that were tolerated in the Roman Empire and anyone was free to worship whoever he wished.

Another thing however is that religion arose in the earliest human civilizations and until the 20th century because it provided an answer (namely "an act of a god") to everything from 'what makes the corn grow, the sun shine and the wind blow?' to 'What may protect me against the many dangers, illnesses etc. that threaten me'?

People in those days had no idea what caused most natural phenomena, from storms at sea to illnesses, and you had to be a very brave - or reckless - person if you decided that you could do totally without the protection of any god. This after all was the time when 50% of all children - rich or poor - died before age 14 and when there was no effective cure against almost all ilnesses.

So most people had their personal 'household gods'' who they hoped and expected would protect them and to whom they made small daily offerings. There was no sanction against not believing, only the fear what might happen if you didn't.