What religion were the Romans when they crucified Jesus?

This answer requires a bit of breaking down. Let me explain if I may. The religion of the Romans during the first century A.D. was polytheistic. This means that they worshipped many gods and goddesses, many of which had a specific patronage. For example Jupiter is the Roman king of the gods and is the god of thunder, Mars is the Roman god of war, Mercury is the Roman god of wealth etc… The Romans saw Judaism, Christianity, and monotheism as superstitious and foolish, namely because of all of the rites, ordinances, observances, and talk of an afterlife, of which, was believed by the Romans to be reserved exclusively for the kings and heroes of Rome.

The reason that this question deserves breaking down, is that while it was a Roman prefect (Pontius Pilate) that ordered Jesus crucified, Jesus’ executioners were Samaritan Jews, so Jesus wasn’t crucified by the “Romans” per se. The auxiliary unit that crucified Jesus, Cohors I Sebastenorum, was a Samaritan unit of palace guards and cavalrymen that were stationed in Judea to protect the prefect. Auxiliary soldiers obtained Roman citizenship after 25 years in the Roman army, so an argument could be made that it wasn’t Romans that crucified Jesus but Samaritans. The prevailing religion in all of Palestine at that time was Orthodox Judaism. So your question has two answers, and the answers are, that politically, Jesus’ crucifixion was ordered by Roman adherents to Roman Polytheism, and he was physically crucified by Orthodox Jews, adherents to the Law of Moses.