In the earliest days of Christianity, many important letters and instructions were penned by the first followers of Christ and were held in great honor by the early Church, while not included in the Canon of Sacred Scripture. The Teaching of the Twelve Apostles, often called the Didache, was the earliest catechetical instruction of its kind, written late in the first century. It instructs the early Christians on all aspects of the Christian life. Lost to modern scholarship until its rediscovery in 1873, the Didache is considered one of the most important early Christian writings known today.