Is there any reason to believe in the bible that comes externally from the bible?
So you're asking for external evidence that the Bible is true? I'll just post from Dr. William Lane Craig summarized by Dr. Peter Kreeft:
William Lane Craig has summarized the traditional textual arguments with such clarity, condensation and power that we quote him here at length. The following arguments (rearranged and outlined from Knowing the Truth About the Resurrection) prove two things: first, that the Gospels were written by the disciples, not later myth-makers, and second, that the Gospels we have today are essentially the same as the originals.
(A) Proof that the Gospels were written by eyewitnesses:
1. Internal evidence, from the Gospels themselves:
The style of writing in the Gospels is simple and alive, what we would expect from their traditionally accepted authors.
Moreover, since Luke was written before Acts, and since Acts was written prior to the death of Paul, Luke must have an early date, which speaks for its authenticity.
The Gospels also show an intimate knowledge of Jerusalem prior to its destruction in A.D. 70. The Gospels are full of proper names, dates, cultural details, historical events, and customs and opinions of that time.
Jesus' prophecies of that event (the destruction of Jerusalem) must have been written prior to Jerusalem's fall, for otherwise the church would have separated out the apocalyptic element in the prophecies, which makes them appear to concern the end of the world. Since the end of the world did not come about when Jerusalem was destroyed, the so-called prophecies of its destruction that were really written after the city was destroyed would not have made that event appear so closely connected with the end of the world. Hence, the Gospels must have been written prior to A.D. 70.
The stories of Jesus' human weaknesses and of the disciples' faults also bespeak the Gospels' accuracy.
Furthermore, it would have been impossible for forgers to put together so consistent a narrative as that which we find in the Gospels. The Gospels do not try to suppress apparent discrepancies, which indicates their originality (written by eyewitnesses). There is no attempt at harmonization between the Gospels, such as we might expect from forgers.
The Gospels do not contain anachronisms; the authors appear to have been first-century Jews who were witnesses of the events.
We may conclude that there is no more reason to doubt that the Gospels come from the traditional authors than there is to doubt that the works of Philo or Josephus are authentic, except that the Gospels contain supernatural events.
The disciples must have left some writings, engaged as they were in giving lessons to and counseling believers who were geographically distant; and what could these writings be if not the Gospels and epistles themselves? Eventually the apostles would have needed to publish accurate narratives of Jesus' history, so that any spurious attempts would be discredited and the genuine Gospels preserved.
There were many eyewitnesses who were still alive when the books were written who could testify whether they came from their purported authors or not.
The extra-biblical testimony unanimously attributes the Gospels to their traditional authors: the Epistle of Barnabas, the Epistle of Clement, the Shepherd of Hermes, Theophilus, Hippolytus, Origen, Quadratus, Irenaeus, Melito, Polycarp, Justin Martyr, Dionysius, Tertullian, Cyprian, Tatian, Caius, Athanasius, Cyril, up to Eusebius in A.D. 315, even Christianity's opponents conceded this: Celsus, Porphyry, Emperor Julian.
With a single exception, no apocryphal gospel is ever quoted by any known author during the first three hundred years after Christ. In fact there is no evidence that any inauthentic gospel whatever existed in the first century, in which all four Gospels and Acts were written.
(B) Proof that the Gospels we have today are the same Gospels originally written:
Because of the need for instruction and personal devotion, these writings must have been copied many times, which increases the chances of preserving the original text.
In fact, no other ancient work is available in so many copies and languages, and yet all these various versions agree in content.
The text has also remained unmarred by heretical additions. The abundance of manuscripts over a wide geographical distribution demonstrates that the text has been transmitted with only trifling discrepancies. The differences that do exist are quite minor and are the result of unintentional mistakes.
The quotations of the New Testament books in the early Church Fathers all coincide.
The Gospels could not have been corrupted without a great outcry on the part of all orthodox Christians.
No one could have corrupted all the manuscripts.
There is no precise time when the falsification could have occurred, since, as we have seen, the New Testament books are cited by the Church Fathers in regular and close succession. The text could not have been falsified before all external testimony, since then the apostles were still alive and could repudiate such tampering.
The text of the New Testament is every bit as good as the text of the classical works of antiquity. To repudiate the textual parity of the Gospels would be to reverse all the rules of criticism and to reject all the works of antiquity, since the text of those works is less certain than that of the Gospels.
Richard Purtill summarizes the textual case:
Many events which are regarded as firmly established historically have (1) far less documentary evidence than many biblical events; (2) and the documents on which historians rely for much secular history are written much longer after the event than many records of biblical events; (3) furthermore, we have many more copies of biblical narratives than of secular histories; and (4) the surviving copies are much earlier than those on which our evidence for secular history is based. If the biblical narratives did not contain accounts of miraculous events, biblical history would probably be regarded as much more firmly established than most of the history of, say, classical Greece and Rome. (Thinking About Religion, p. 84-85)
From: Evidence for the Resurrection of Christ
