Decius was not very fond of the newly emerging religion, the Christianity, but also of all the other religions that were not Roman. In order to make the people give up on their beliefs and accept the Roman beliefs and culture, Decius made a law. The law was that all the people will be able to chose between their own beliefs (Christianity and the others) and death. Now this law was pretty much set in order to terrify the people because if they chose their religion it meant that they were going to end up dead, so most of them practiced their beliefs in secrecy. It most commonly referred to as a lawful action by Decius in order to stop the Christianity, but in fact it was meant for all the religions in the Roman Empire that were not in accordance to the Roman beliefs and religion.