Jesus told his disciples that he will return only once and that when he does, after a time of great tribulation, it will be visible to everyone and be followed by immediate and dire consequences for those unprepared and for those who were adversaries of God.
The world has received the Word of God, assembled in the Book of books, the bible as the most important and only source of life and source of holiness or set apartness.
When men let their faith and confidence in the credibility of the Word of God get away from them, there is danger of lowering their ethical standard. A tottering faith in the Bible narratives shall bring morality to be unstable and to stagger also. When there is a rejection of the integrity of the Old Testament narratives there shall be no vibration to come to see the truth of this life and the person shall move or sway unsteadily or unsure in this materialist world were more and more people are moving away from God and are having their egoism being the base of their life disturbing their relationships, making them unstable.
Since the 19th century the people who very suspicious because they did not see historical evidence could find one city after another, one civilization after another, one culture after another being found and restored to their proper places in ancient history by the studies of archaeologists and Bible scholars like Botta, Layard, Wellhausen, Winckler, Taylor, Archer a.o..