I can provide three directions of arguments:
- External confirmation
Although the bible was not written explicitly for historical or scientific accuracy, there are many details contained in the bible that are now proven by archaeology. Some examples are location of ancient cities, evidence of wars and large scale disasters, etc. It seems therefore that if the historical records, many of them not recorded elsewhere or may seem improbable are checking out with more and more archaeological evidence, then maybe the whole message should be taken as credible.
- Internal integrity
The Bible is not one book by one human author, but a collection of 73 books written over thousands of years, from many various geographical areas and by many different people. Many of the human authors, therefore, would not have been able to corroborate with the other human authors. They definitely could not corroborate with those who would be writing in the future, but in many the case, they would not have read those who were written before them or contemporary to them, since the books were not all collected together as they were written. Yet what we found is that consistently they were testifying to the same events and details. Most importantly, Old Testament writings often predict details of the events of Jesus that could not be deliberately engineered, like where Jesus was born, where he grew up, how he were to suffer and die — these are all beyond human control. And there are many things like that.
- The seamless garment argument
A traditional argument about the Catholic faith is that everything the Church teaches, interlocks with everything else like a seamless garment. You cannot deny one teaching of the Church without unravelling the whole faith and eventually you will have to deny the whole faith. So either you believe everything or you don’t. A careful examination of the Bible proves to be the same. The Word of God, when interpreted authentically, is an integral whole. Everything speaks to the same truth about God. You simply cannot take it apart. And the amazing fact that it is written as separate books by separate human authors is staggering. Either it is an elaborate hoax spread over thousands of years that defy human control and power, or one has to admit that all the human authors were under one divine orchestration.