"When we ask the question, “What is theology?”
the word’s etymology offers us helpful insight.
The word theology comes from the Greek and means “God-talk” (theos = “God”; logos = “word”).
Hence, theology describes what we do: We talk about God.
Better yet, we have conversations about God.
Theology is communal; it belongs to the life of faith in the ongoing Christian community, stemming from the revelation of Jesus two-thousand years ago."
(J.J. Mueller, “Introduction,” Theological Foundations, p. 1)
Linguistically simplistic. As you know, logos has a wide range of meaning. You could just as easily say it is the message of God as "talking about God." I'll stick with the traditional gloss, "the study of God." That fits our 21st century usage better, and avoids the root fallacy.
I think we are all in agreement, theo refers to God.
However, logy is said to be a form of logos.
But as JOJ pointed out, now days most think logy means study.
So theology means God study.
So the question boils down to what does logy mean and how did it come to mean study?
Perhaps the idea is to speak on a topic, so theology would be to speak on the topic of God?
But to speak on a topic presupposes one knows something about the topic.
Then there the question of Yahweh, the one and only God, or the many other gods.
So I could speak on the topic of some Greek god, and that would be theology, would it not.
Or is theology restricted to speaking about Yahweh.