In 70ad the temple was destroyed just as Jesus predicted. Was it a act of God? Or a act of man? And why?
The temple destruction of 70 AD was prophesied by Jesus and he said that not a stone would remain un-turned. He also told the all the citizens of Jerusalem that when they saw the city surrounded on three sides to get out.
This is the same scenario repeating itself when in the last 42 months of GT, Revelation tells all who are in Jerusalem at the time of the 'abomination of desolation' to get out.
Titus was the Roman (Daniel's Beast) General responsible for the fall of Jerusalem and the Temple. He (Titus) had to return to Rome and the Roman army at this time had already surrounded Jerusalem on three sides at this time. For a period of time, while Titus took care of business at home, the Roman army simply camped where they were at.
There is one interesting point to consider. Over 1 million people died here but not one Christian died. From archives, all the Christians took Jesus at his word and removed themselves from the city via the open fourth side.
As far as the prophecy that "no stone would go un-turned", this too was fulfilled. Why? because the temple had Gold on its walls, ceilings, floors, etc. When the temple burnt, the gold being a soft metal, melted and ran down in the cracks between the stone flooring and the Beast of Daniel wanted the gold. Thus No stone was un-turned.
To answer the last question I will ask with a question! When have you as a Christian, seen any event (in the world) including individual actions of every Christian (believers) that did not have God's hand in it?