Architecture of Kievan Rus' was exemplified by Byzantine masters building their first cathedrals in the realm, and decorating their interiors with mosaics and murals.
The metropolitan Hilarion of Kiev wrote his work Sermon on Law and Grace (Slovo o zakone i blagodati) in the mid-11th century, confirming the basics of Kievan Rus' new Christian world outlook.
The Rus' principalities adopted the Byzantine culture during a time when the apogee of the Eastern Roman Empire had already been overcome, but its decline was still far ahead.
Byzantium remained the only direct successor of the Hellenistic world, which had applied the artistic achievements of antiquity to the spiritual experience of Christianity.
Byzantine influence, however, couldn't spread quickly over the enormous territory of Rus’ lands, and their Christianization would take several centuries.
Subsequently, it was defined by a simplified interpretation of Christianity and by superstitions, similar to what had happened in Western European culture.
At the same time, the culture of the ecclesiastical and secular elite is known for its monuments, which do not allow historians to make confident conclusions on pagan penetration of religious beliefs of Medieval Rus’.
They certainly give credit to the earlier traditions of the Early East Slavs and Finnic peoples without, however, overestimating their significance in forming elements of the culture.
That is, although the Rus would have had access to the vast libraries of Greek philosophy, mathematics, and science housed there; there is no evidence that they translated any of these into Slavonic.