Pliny the Younger's (61-112 CE) letter (Epistulae X.96) to Roman Emperor Trajan (r. 98-117 CE) is one of our earliest sources on Christianity from an outsider's point of view. It highlights the Christian movement's impact on the old Roman religion and provides the earliest historical evidence for Christian trials.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/1846/pliny-the-younger-on-christianity/.