What does Theodosius mean by belief in one deity?

Theodosius, a Roman Emperor known for his staunch support of Christianity, emphasized belief in one deity as a reflection of monotheism, which asserts the existence of a single, all-powerful God. This belief was fundamental to unifying the Roman Empire under a common religious framework, particularly as Christianity spread. By promoting this idea, Theodosius sought to strengthen the authority of the Christian church and diminish pagan practices, reinforcing the notion that true worship should be directed solely towards one divine entity.