One of the most powerful and mysterious writings of the early church is something called THE LETTER TO DIOGNETUS. It is an anonymous letter written in the 2nd century, less than 50 years after the end of the New Testament era.
What makes it so unique is that it is the first letter or “epistle” NOT addressed to fellow Christians, but rather to a pagan. Because of that, it serves as the one of the earliest accounts of how the early church shared their faith with non-believers and presented the good news of Jesus Christ to the world around.