First let me answer this for you, then I will set out to show you Scriptures proof. If a man tells you that God says that X will happen in the future, and X does not happen; then that man is a false prophet. So, this means that there are false prophets in the church today. I could be one because I am dogmatic in my conclusion that the post-Trib Rapture is Scriptures teaching. Others could be false prophets because they are dogmatic in teaching that the rapture will be pre-Trib. That makes this a very serious subject to God, and to us. So what does scripture say about false prophets?

2 Peter 2:1 But false prophets also arose among the people, just as there will also be false teachers among you, who will secretly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction upon themselves.
False prophets can certainly arise among us in the body of Messiah. Paul had basically told the Ephesians the same when He for the last time met with their elders — Acts 20:29-30 I know that after my departure savage wolves will come in among you, not sparing the flock; and from among your own selves men will arise, speaking perverse things, to draw away the disciples after them.
Synonyms of perverse are the terms: illogical, irrational, unreasonable, and wrong.
In his book THE INCOMPLETE CHURCH, Sid Roth lays out the case for a conspiracy to separate the church from Israel.  The truth of scripture is not found in Israel and the church being separate. Neither is it found in the Church being a replacement for Israel, but it is found in one new man (Eph. 2).
Sid asks “Could the Church be under a family curse…? Has the Church denied its Jewish heritage? Yes… This was not an accident. It was part of a deliberate plan to separate the Church from anything Jewish.” p.64

In the book I wrote which is the reason I established this site, I have taken the position that there is no way to prove with direct statements from Scripture that there is any separation of those accepting the New Covenant. There is no salvation apart from the New Covenant in Jesus’ blood. No separation of Gentile from the Jewish believers in Messiah, and there is certainly no way without definite Scriptural teaching of that separation to prove a Rapture that is not connected to the resurrection occurring at the second coming of our Messiah. Therefore there is no Scriptural proof for a pre-Trib Rapture of the Church. There is Scripture to prove that God’s wrath will not touch the Church, but one cannot prove that the Great Tribulation is God’s wrath; although this is the argument.
Yet, Christian teachers whom I respect in so many ways teach this position dogmatically. Listen to one teacher that I love: “Revelation 13 talks about global government. There it states that the Antichrist will have control over every language, and tribe and nation (verses 6-8). Chief globalist David Rockefeller, now deceased, kept talking about the fact that a crisis will be needed in this system, which will likely be Marxism. The crisis will not be a war or financial collapse. It will be the Rapture. (Taken from Olivetree Ministries weekly email news letter for this week)
If this is the case the Rapture must be pre-Tribulational. So my questions are I think significant. I have pondered these questions ever since I turned my back on pre-Trib Dispensational theology, and I think one of these questions is pondered for good reason. I’ll deal with the reason after revealing the question which is — Is not a dogmatic teaching of any one of the positions Pre-Trib; Mid-Trib or Post-Trib really false Prophecy if it proves in the end to be wrong?
So why do I say this? — what is the reason why I ponder this? Consider: in Scripture when men rely on a prophecy to their own detriment the prophet is always condemned as false. And when a person gives a teaching concerning God’s message of the future it is always considered a prophecy. So just how important is it for me to be sure that God’s word support my teaching? Listen to what God says concerning prophets:
Jeremiah 14:13-14 But, “Ah, Lord God!” I said, “Look, the prophets are telling them, ‘You will not see the sword nor will you have famine, but I will give you lasting peace in this place.’” Then the Lord said to me, “The prophets are prophesying falsehood in My name. I have neither sent them nor commanded them nor spoken to them; they are prophesying to you a false vision, divination, futility and the deception of their own minds.
So herein rests the problem. When man or woman says that there is no way to prove the Rapture is pre, mid, or post, yet they proceed to teach one over the others, then by definition they are every bit as much a false prophet as one who says that God has said what God has never said. I believe that the scripture is so clear on post-trib Rapture that I have never stated it to possibly be false. Some believe this to be speaking from an arrogant state of mind, but my question is this — is it arrogant to believe God and His word? To me it is foolish to not believe God.
Some tell us that to them Wrath is the key. So listen to one pre-Trib believer tell us about Tribulation.
“He will be the last dictator after centuries of ruthless leaders. No one, not even Hitler, will be able to compare to the Antichrist. He will control the economy (Revelation 13:16-17). He will be a destroyer who will come against Israel and try to wipe her out after first pretending to be their friend. He breaks one treaty after another. His power comes from Satan.”

She goes on: “The counterfeit kingdom cannot blossom until the Church is removed in the Rapture. But we’re watching it gear up as though it could manifest tomorrow. And maybe it will.”
So when I see Satan as the purveyor of wrath in the Tribulation this view is at least not unheard of even among Pre-Trib scholars. But if during the Tribulation they overcome him with the blood of the Lamb and the word of their testimony, who then are they? And if they are believers in Jesus and partakers with us in the new covenant how then can we think that God will deliver us but not them?
Ezekiel 13:2-3, 5-6 “Son of man, prophesy against the prophets of Israel who prophesy, and say to those who prophesy from their own inspiration, ‘Listen to the word of the Lord! Thus says the Lord God, “Woe to the foolish prophets who are following their own spirit and have seen nothing. You have not gone up into the breaches, nor did you build the wall around the house of Israel to stand in the battle on the day of the Lord. They see falsehood and lying divination who are saying, ‘The Lord declares,’ when the Lord has not sent them; yet they hope for the fulfillment of their word.
Who are the prophets today who hope for the fulfillment of their teaching?
Luke 6:26 Woe to you when all men speak well of you, for their fathers used to treat the false prophets in the same way.
Who are the prophets within the church of today who are believed and respected by most Christians who “hope for the fulfillment of their word”?
James 3:1 Let not many of you become teachers, my brethren, knowing that as such we will incur a stricter judgment.
I take these words seriously, if a Christian is guilty of false Prophecy we know that he or she will incur a strict judgment. In fact according to Paul the very works that they build upon Jesus (the word) the foundation of our faith can be burned up and all that is left is ones salvation though as by fire (1 Cor 3:10-15).