Christian writings not included in the authoritative canon of the NT which claim to be reminiscences of the life of the young Jesus and his miraculous powers, or supplements to the book of Acts about apostles who were there passed over. Several epistles and apocalypses also exist. Although these works, deriving from the 2nd to the 9th cent., in Greek, Latin, Syriac, and other languages, give little reliable information about Christian origins, they do contribute to our understanding of Christian thought and the life and piety of these centuries. The discoveries at Nag Hammadi in 1945 have revealed many previously unknown apocryphal documents, some of which purport to give Christ's teaching to the disciples between the resurrection and ascension (the period is conveniently lengthened from 40 to 550 days).

Several of the non-canonical gospels (e.g. the Gnostic Gospel of Thomas and the Gospel of Truth) contain stories about the birth and infancy of Jesus. However, these lack parallels with substantial teaching material which is prominent in the synoptic gospels, e.g. Jesus' compassion and care for people, though among the 114 sayings attributed to Jesus in Thomas are several, e.g. ‘He who is near me is near fire but he who is far from me is far from the Kingdom’ (known to Origen), and ‘split the wood and I am there; lift up the stone and you will find me there’ commend themselves for authenticity.