The Fact of the Rature
First, we must look at the fact of the Rapture. Many have argued, rightfully so, that the word Rapture is not even found in the Bible. Well, neither is the word trinity or grandfather, but no one is in doubt as to there existence. So that argument simply does not hold any water in the discussion of the subject at hand.
While the word Rapture does not exist in our English Bible, the Greek word “harpazo” does. We find this word in 1 Thessalonians 4:13-18 were it says, “But I do not want you to be ignorant, brethren, concerning those who have fallen asleep, lest you sorrow as others who have no hope. For if we believe that Jesus died and rose again, even so God will bring with Him those who sleep in Jesus. For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord will by no means precede those who are asleep. For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first. Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord. Therefore comfort one another with these words.” The word for “caught” in verse 17 is the Greek word “harpazo” with means to seize, catch (away, up), pluck, pull, take (by force). 
We also see the fact of the Rapture in 1 Corinthians 15:51-52 were it says, “Behold, I tell you a mystery: We shall not all sleep, but we shall all be changed -- in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised incorruptible, and we shall be changed.”
There are also places in Scripture were we see foreshadows of the Rapture in the Old Testament. The first of which is in the “taking” of Enoch in Genesis 5:24. The Bible says that “…Enoch walked with God; and he was not, for God took him.”
Enoch was quite literally raptured because of his unique relationship with his God. God decided to transport Enoch directly to Heaven without first having him taste death. This same thing will happen to all of those who call upon the name of Jesus Christ one day because of our special relationship with God.
We see it again in the life of the prophet, Elijah. The Bible tells us in 2 Kings 2:11-12, “Then it happened, as they continued on and talked, that suddenly a chariot of fire appeared with horses of fire, and separated the two of them; and Elijah went up by a whirlwind into heaven. And Elisha saw it, and he cried out, "My father, my father, the chariot of Israel and its horsemen!" So he saw him no more. And he took hold of his own clothes and tore them into two pieces.”
So, we too as children of God have a unique place in God’s economy and one day He will come back and take us home with Him. It was a promise that He made in John 14:2-3 when He said, “In My Father's house are many mansions; if it were not so, I would have told you. I go to prepare a place for you. And if I go and prepare a place for you, I will come again and receive you to Myself; that where I am, there you may be also.”
These instances are a foreshadowing of a yet future event when millions of Christians will suddenly and seemingly without notice be caught away into Heaven without every tasting death. This event is called the Rapture.
 Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary. Copyright (c) 1994, Biblesoft and International Bible Translators, Inc.