Even though future generations might regard the Roman Empire as great and prosperous, in reality, they are not entirely wrong.
But the riches could only be shared by the minority of "citizens."
What kind of people were the earliest Christians?
The most destitute in Rome.
Freemen living in the cities, bankrupted across various trades, or newly freed slaves. Slaves from vast estates, and small farmers increasingly trapped in debt and servitude.
For all these people, there was absolutely no common path to liberation. For all these people, Heaven was a lost cause; the freemen's Heaven was the past City-State where their ancestors freely thrived; the prisoner slaves' Heaven was the era of freedom before capture and enslavement; the smallholder's Heaven was the extinct clan system and communal land ownership.
Thus, at that time, the only way out was in the realm of religion.
The theologians opened a crack leading to dreams amidst the despondent present world.