The first sign that Jesus mentioned is found in the World (War, Natural Disasters and Famines);
The second sign is found in the Church (Universal Persecution of Christians, the Great Falling Away of many Christians, the Rise of False Prophets and Teachings);
The third sign is found in Jerusalem (the rise of the Anti-Christ or Man of Lawlessness in Jerusalem).
And the final sign is found in the sky where the sun, moon and stars will all black out and they will be total darkness and immediately after this, Jesus will return.
