One of the biggest mysteries in the Bible concerns the timing of Jesus Christ's return to earth. Although the Bible tells us no one knows the hour nor the day when the Lord will return, the Bible is filled with many indicators or conditions we can use to assess how close we may be to the season of His return.
The signs are as follows:
1. The Gospel will be preached in all the world before the physical return of Jesus Christ to the earth occurs at Armageddon, although exhaustive efforts are presently underway to accomplish this:
Matthew 24:14: And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.

2. There will be a mixture of believers and false believers within the Church body:
Matthew 13:24-30: Another parable put he forth unto them, saying, The kingdom of heaven is likened unto a man which sowed good seed in his field: But while men slept, his enemy came and sowed tares among the wheat, and went his way. But when the blade was sprung up, and brought forth fruit, then appeared the tares also. So the servants of the householder came and said unto him, Sir, didst not thou sow good seed in thy field? from whence then hath it tares? He said unto them, An enemy hath done this. The servants said unto him, Wilt thou then that we go and gather them up? But he said, Nay; lest while ye gather up the tares, ye root up also the wheat with them. Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.

3. There will be scoffers:
The Bible tells us one of the key signs of the end times will be people doubting the return of Christ will ever happen.
2nd Peter 3:3-4: Knowing this first, that there shall come in the last days scoffers, walking after their own lusts, And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation.

4. There will be increase in travel and knowledge(Science and technology):
Daniel 12:4: But thou, O Daniel, shut up the words, and seal the book, even to the time of the end: many shall run to and fro, and knowledge shall be increased.

5. Perilous times will come for mankind:
2nd Timothy 3:1: This know also, that in the last days perilous times shall come.

6. Mankind will deny God once flooded the earth:
2nd Peter 3:5-6: For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water: Whereby the world that then was, being overflowed with water, perished:

7. The earth will be swimming in a sea of violence:
As it was in the days of Noah (Luke 17:26), so it shall be at the end. How was the earth in Noah's time?
Look no further than Genesis 6:11: The earth also was corrupt before God, and the earth was filled with violence.

8. There will be warfare all over the globe:
Mark 13:8: For nation shall rise against nation, and kingdom against kingdom:

9. Mankind will have the capability to destroy all life on the planet:
Unique to our generation, this prophecy could not have been fulfilled prior to the invention of weapons of mass destruction such as the nuclear bomb. Matthew 24: 22: And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened.

10. Deadly diseases will be rampant:
Matthew 24:7: For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places.

11. Famines will be common:
Matthew 24:7: For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places.

12. Earthquakes will be occurring globally:
Matthew 24:7: For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places.

13. There will be violent weather:
Luke 21:25- And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring;

14. Children will be disobedient and rebellious:
2nd Timothy 3:2: For men shall be lovers of their own selves, covetous, boasters, proud, blasphemers, disobedient to parents, unthankful, unholy,
15. Christians and Jews will be hated for their faith in and connection with Christ:

Luke 21:17: And ye shall be hated of all men for my name's sake.

16. Mankind will be in a state of moral, spiritual decay:
2nd Timothy 3:2-5: For men shall be lovers of their own selves, covetous, boasters, proud, blasphemers, disobedient to parents, unthankful, unholy, Without natural affection, trucebreakers, false accusers, incontinent, fierce, despisers of those that are good, Traitors, heady, highminded, lovers of pleasures more than lovers of God; Having a form of godliness, but denying the power thereof: from such turn away.

17. Religious cults will flourish:
2nd Peter 2:1: But there were false prophets also among the people, even as there shall be false teachers among you, who privily shall bring in damnable heresies, even denying the Lord that bought them, and bring upon themselves swift destruction.

18. There will be progress made toward a global government:
The European Union, the revived Roman Empire, is alive today and moving steadily toward the fulfillment of this prophecy as seen in Daniel 7: 23: "The fourth beast shall be the fourth kingdom upon earth, which shall be diverse from all kingdoms, and shall devour the whole earth, and shall tread it down, and break it in pieces." The Antichrist who will lead this world government (after the rapture of the Christian Church takes place) will be (or become) leader of the European Union as seen in Daniel 9:26. He will be a descendant of the people who destroyed the city of Jerusalem and its sanctuary in AD 70, the Romans.

19. The world will be desperately seeking peace:
1st Thessalonians 5:3: For when they shall say, Peace and safety; then sudden destruction cometh upon them, as travail upon a woman with child; and they shall not escape.

20. Global means of communication will exist:
We know this because the book of Revelation teaches us the entire world will see several events. This is unique to our generation as only recently in mankind's history have these technologies been present.
Revelation 11:9: And they of the people and kindreds and tongues and nations shall see their dead bodies three days and an half, and shall not suffer their dead bodies to be put in graves.

21. In the last days, fallen angels will mingle with mankind:
I know this one is going to be controversial, but there is a scriptural basis for this, as seen in Luke 17:26: And as it was in the days of Noe, so shall it be also in the days of the Son of man.
A careful examination of what was going on in Noah's day seems to suggest fallen angels were somehow mingling with mankind.
Genesis 6:4: There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
If so, one of God's motives in destroying mankind at the flood may have been Satan and his fallen angels, in an attempt to save themselves from His judgment, were trying to taint the bloodline that would lead to the birth of Christ.
We find Noah was spared from destruction for three reasons as seen in Genesis 6:9. They are as follows:
1) Noah was a just man.
2) Noah was perfect in his generations (note this reference to his bloodline being pure).
3) Noah walked with God.
There is potentially more to the numerous UFO sightings and alien abduction stories in the news today than we have ever imagined!

22. Israel will exist as a nation in the latter days:
Read Ezekiel 37:1-14 to see this prophecy, which was fulfilled in 1948.

23. Israel's birth as a nation will have happened in one day:
Fulfilled on May 14, 1948 as seen in Isaiah 66:8: "Who hath heard such a thing? who hath seen such things? Shall the earth be made to bring forth in one day? or shall a nation be born at once?"

24. Israel will be in possession of Jerusalem (has been since 1967):
This happened as a result of the Six-Day War in 1967. The capture of Jerusalem was critical from a prophetic standpoint as the Antichrist will someday enter a rebuilt Holy Temple that will be standing in Jerusalem at the midpoint of the Tribulation Period where he will declare himself to be God. This event, referred to by most as the abomination of desolation, is documented in Daniel 9:27 and Matthew 24:15.

25. Israel will be surrounded on every side by enemies:
Psalms 83:4: They have said, Come, and let us cut them off from being a nation; that the name of Israel may be no more in remembrance.

26. The possession of Jerusalem will be the source of international conflict:
Is this happening today or what? It's a HUGE sign to us! Zechariah 12:3: And in that day will I make Jerusalem a burdensome stone for all people: all that burden themselves with it shall be cut in pieces, though all the people of the earth be gathered together against it.

27. Christians will be lukewarm in their faith:
In Christ's address to the seven churches, He says in Revelation 3:15: I know thy works, that thou art neither cold nor hot: I would thou wert cold or hot.

28. Many will claim to be Christ:
Matthew 24:5: For many shall come in my name, saying, I am Christ; and shall deceive many.

29. False Christs and false prophets will be very effective in the art of deception:
Matthew 24:24: For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.

30. There will be signs in the heavens:
Luke 21:25: And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring;

31. Mockers will abound because those who live according to their own desires love to mock those who try to live theirs in a manner pleasing to God.
Jude 1:18: How that they told you there should be mockers in the last time, who should walk after their own ungodly lusts.

32. Idolatry will be common:
Revelation 9:20: And the rest of the men which were not killed by these plagues yet repented not of the works of their hands, that they should not worship devils, and idols of gold, and silver, and brass, and stone, and of wood: which neither can see, nor hear, nor walk:

33. Many Christians and church doctrines will depart from the faith:
1st Timothy 4:1: Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils;

34. Mankind's state of rebellion will be so great, the coming of Christ will catch them completely off-guard:
Luke 21:35: For as a snare shall it come on all them that dwell on the face of the whole earth.

35. Homosexuality will be flaunted:
Leviticus 20:13: "If a man also lie with mankind, as he lieth with a woman, both of them have committed an abomination: they shall surely be put to death; their blood shall be upon them."
This is also spoken of in Luke 17:28- 30: "Likewise also as it was in the days of Lot; they did eat, they drank, they bought, they sold, they planted, they builded; But the same day that Lot went out of Sodom it rained fire and brimstone from heaven, and destroyed them all. Even thus shall it be in the day when the Son of man is revealed."
Although homosexuality is an abomination in the eyes of God, all sin is! I bring up this point because many Christians treat homosexuality as if it is the most unforgivable sin of all. Jesus Christ forgives all sins and we, His followers, should be reaching out to these people with love in our hearts that they might be saved! Homosexuality is not an unpardonable sin any more than any other sin is!

36. Many will rejoice in their unrighteousness:
2nd Thessalonians 2: 12: "That they all might be damned who believed not the truth, but had pleasure in unrighteousness."
These people, according to 2nd Thessalonians 2:11, will be subject to believing the lie the Antichrist will present to the world in the aftermath of the Rapture of the Church, leading many of them to eternal damnation. God will allow them to be deceived, it seems, as a reward for their bold defiance of Him. What a frightening thought!

37. Aliyah will be taking place:
What is Aliyah? Aliyah is the Hebrew word used to describe the physical return of the Jewish people, the children of Israel, to their ancient Promised Land, Zion, from abroad.
In Scripture, God promised He would bring the Jews (descendants of Abraham) back to their Promised Land from all the nations of the world where He had scattered them! It is happening even as you read these words.
Ezekiel 36:24: For I will take you from among the heathen, and gather you out of all countries, and will bring you into your own land.

39. There will be signs Earth's environment is in trouble:
Romans 8:21-23: Because the creature itself also shall be delivered from the bondage of corruption into the glorious liberty of the children of God. For we know that the whole creation groaneth and travaileth in pain together until now. And not only [they], but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, [to wit], the redemption of our body.

40. Technology will exist capable of tracking the world's population, finances.
Revelation 13:16-17: And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads: And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name.

41. The capability will exist for an army of 200 million soldiers to be formed:
In Revelation 9:16, John sees a specific number of soldiers/"horsemen" preparing for or entering into war: And the number of the army of the horsemen were two hundred thousand thousand: and I heard the number of them.
Estimates of the total human population of Earth during Christ's day typically vary between 100 to 400 million people. In 2004, the CIA determined China had an estimated 208,143,352 in its population alone fit for military service. As of 2006, that number had risen to 281,240,272 men fit for military service.

42. Drug use will be rampant:
Revelation 9:21: Neither repented they of their murders, nor of their sorceries, nor of their fornication, nor of their thefts.
The original Greek for the word 'sorceries' is pharmakeia {far-mak-i'-ah}. It means the use of or the administering of drugs OR sorcery, magical arts, often found in connection with idolatry and fostered by it.

43. Evil men, seducers and deceivers will get worse and worse. (2nd Timothy 3:13)
One doesn't have to think too hard to realize this prophecy is being dramatically fulfilled in our times. Upon reading this, close your eyes for a moment and think of how many people you know (or have heard of from reputable sources) who seem to be evil to the core! Similarly, think of how many people you know who have fallen victim to frauds and scams perpetrated by seducers (deceivers/imposters). The world today seems full of these types with no letup in sight.

44. There will be wars and rumours of war.
Matthew 24:6: And ye shall hear of wars and rumours of wars: see that ye be not troubled: for all [these things] must come to pass, but the end is not yet.
It seems that for every international conflict that exists at a given moment in our present time, there is potential for another to manifest itself as well. It's as though our world is about to blow apart at the seams!

45. When we begin to collectively see the signs listed above, Christ's return is not only near but is here!
Luke 21:28: And when these things BEGIN to come to pass, then look up, and lift up your heads; for your redemption draweth nigh.