Today is the feast of St. Ephrem the Syrian, Doctor of the Church. Born in Nisibis (modern-day Nusaybin, Turkey), there's some confusion about whether his family was pagan or Christian, but he was baptized at an early age and became what in the Syrian Church of the day was called a 'son of the covenant'. Monasticism was not yet part of the Christian culture in that part of the world; what they had instead was a group of men and women who would 'covenant' to engage in basic ascetic practices and serve the local church community through charitable practices. At some point he became a catechist and a deacon. By tradition, he is regarded as the founder of the School of Nisibis, one of the most important institutions in early Syrian Christianity, but we don't know whether this is literal or just a figurative expression of how important he ended up being for it.
The area in which Ephrem lived was highly contested between the two major powers of the day, the Roman Empire and the Persian Empire. For Ephrem's early life, Nisibis was under the authority of Rome, which had recently seized it, but after the death of Constantine in 337, Shapur II of Persia laid a series of campaigns to reclaim it, with Rome engaging in counterclaims. The definitive shift was with the death of Julian the Apostate in battle against the Persians in 363; the next emperor, was forced to negotiate a truce in which Nisibis was handed over to Persia and its Christian population (who were seen as having ties that were too close to the Romans) were expelled. Ephrem ended up in Edessa (modern-day Urfa, Turkey); he would have been somewhere around the age of fifty. Edessa was a riot of opposing philosophies and sects, so Ephrem set out to defend Nicene orthodoxy and oppose a number of major heresies, which he did by means of doctrinal hymns -- theological summaries in the local Aramaic dialect that could be sung to Syriac folk tunes. He is generally thought to have died about 373 from a plague in which he was nursing the sick. He is one of the most influential theologians in history, being a major influence on churches in the Syriac traditions.
The following is from the Hymn Against Bar-Daisan. Bar-Daisan was one of the most brilliant minds in Edessa from the century before Ephrem, an extraordinary polymath. He was Christian, at least originally, but he blended Christian ideas with ideas from Babylonian astrology, giving his theology a Gnostic structure. We don't know all the precise details of his doctrines, though, although it seems fairly certain that he denied the resurrection of the body. He founded his own sect on these ideas, and it spread like crazy. Ephrem had some temporary success against it, but it survived and was still going strong in Edessa several centuries later. It lasted at least until the twelfth century in its own right; it also was a major influence on other heretical sects like Manichaeism (Mani was in the next generation after Bar-Daisan).
There is One Being, who knows Himself and sees Himself.
He dwells in Himself,
And from Himself sets forth.
Glory to His Name.
This is a Being who by His own will is in every place,
Who is invisible and visible,
Manifest and secret.
He is above and below.
Mingling and condescending by His grace among the lower;
Loftier and more exalted, as befits His glory, than the higher.
The swift cannot exceed His swiftness,
Nor the slow outlast His patience.
He is before all and after all,
And in the midst of all.
He is like the sea,
In that all creation moves in Him.
As the waters beset the fish in all their movements,
The Creator is clad with everything which is made,
Both great and small.
And as the fish are hidden in the water,
There is hidden in God height and depth,
Far and near,
And the inhabitants thereof.
And as the water meets the fishes everywhere it goes,
So God meets everyone who walks.
And as the water touches the fish at every turn it makes,
God accompanies and sees every man in all his deeds.