The Sermon on Law and Grace is a sermon written by the Kievan Metropolitan Hilarion. It is one of the earliest Slavonic texts available, having been written several decades before the Primary Chronicle. Since Hilarion was considered to be a writer worthy of imitation, this sermon was very influential in the further development of both the style and content of Kievan Rus' literature.

The Christianization of Kievan Rus' was a long and complicated process that took place in several stages. In 867, Patriarch Photius of Constantinople told other Christian patriarchs that the Rus' people were converting enthusiastically, but his efforts seem to have entailed no lasting consequences, since the Russian Primary Chronicle and other Slavonic sources describe the tenth-century Rus' as still firmly entrenched in Slavic paganism. The traditional view, as recorded in the Russian Primary Chronicle, is that the definitive Christianization of Kievan Rus' dates happened c. 988, when Vladimir the Great was baptized in Chersonesus (Korsun) and proceeded to baptize his family and people in Kiev. The latter events are traditionally referred to as baptism of Rus' in Russian, Ukrainian and Belarusian literature.