During the first generation of Christian leaders, referred to as the Church Fathers, we find numerous quotes of the New Testament from their personal correspondence. For example, Clement of Alexandria, who lived about AD 150 - AD 212, has 2,406 quotes from all but three books of the New Testament. Tertullian, who was an elder of the church in Carthage and who lived around AD 160 - AD 220, quotes the New Testament 7,258 times. Of these quotes, around 3,800 are from the gospels. Other quotes from Church fathers include Justin Martyr, 330 quotes; Irenaeus, 1,819 quotes; Origen, 17,922 quotes, Hippolytus, 1,378 quotes; and Eusebius, 5,176 quotes, making a total of 36,289 quotes of the New Testament.
What is interesting and significant about these numerous quotes of the New Testament is that you could destroy all the manuscripts of the New Testament, and destroy all the New Testaments in existence in the world, and you could reproduce all but eleven verses of the New Testament from these quotes of the Church Fathers.
Thus, when it comes to checking and cross checking the readings of the New Testament, it stands as the most historically attested to work of the ancient world.
The Historicity of the Bible (http://answeringislam.org/Case/case1.html)