To answer such a question, let’s start by looking at the word RELIGION. It comes from Latin RE-LIGARE, which means to Re-Connect. The word was termed to explain a human urge to be reconnected to his creator, to his origin.
So what started as a basic human instinct has developed into temples, rituals, texts, statues and a lot of division. That’s exactly what religion means to us nowadays, and in that sense of the word, then no, a stoic is not religious.
The stoic context of many gods
Reading through Seneca’s letters and Epictetus’s discourse, we find various mentions of God and gods. However, it is important to distinguish between them. To do as such we need to remember what those words meant in early Greece and Rome.
At that time, we have no records of a monotheist religion (one true God); this concept emerges with Judaism. Greeks and Romans would pray for their ancients and for each particular god depending on what they had dominion over.
A beautiful example, in my humble opinion, is Achilles praying to the Greek God of War Aires (Mars, for the Romans) whenever going to battle. You see that in the movie TROY, starring Brad Pitt as Achilles.
At that time, people believed that gods could explain natural phenomena. If there was a good harvest it would mean Demeter (Ceres, for the Romans) was happy and rewarded people. In contrast, if there was a flood, Poseidon or Neptune was upset. And so on.
A stoic God
You won’t find many stoic writings discussing the many gods and people’s beliefs. What we can find are mentions of a God, easily substituted by many meaningful names, that refers to human origin, to where we come from, and actually explains and gives meaning to our existence.
As we can read in Seneca’s 65, he says:
“Our Stoic philosophers, as you know, declare there are two things in the universe which are the source of everything – namely, cause and matter. (…) The Stoics believe in one cause only – the maker; (..) Now, however, I am searching for the first, the general cause; this must be simple, inasmuch as matter, too, is simple. Do we ask what cause is? It is surely Creative Reason, in other words, God.”
With that in mind, we realize there is no foundation for cult in Stoicism. It is more of a significant explanation of how it all begins and of why every mechanism in the universe, nature and men, was designed to perfection. There had to be an intelligent cause behind its logic.
Stoicism’s application to all belief systems
According to Massimo Pigliucci, Stoicism has the possibility of being an ecumenical philosophy, which means it can be applied to any religion we know and also with atheism. If you have noticed, there is no metaphysical explanation of the Primary Cause (God). It is a reasonable conclusion.
There is a lot of sense in what Pigliucci says. Stoicism is about bringing the best of one self to serve society. It is about self-development and control impacting directly on human life, nature and the universe.
Obviously, some religions will converge more easily to the stoic ideals than others. We just have to remind ourselves of the difference between belief in God and the real meaning of religion.