An argument that is often used against the idea of the Rapture occurring near or at the end of the Tribulation is that such a return would not be a surprise as Jesus (supposedly) said it would be, because such a return could be anticipated by the events of the Tribulation. There must be a pre-tribulation Rapture, they say, otherwise the believers would not need to be ready and stay alert as Scripture says they should, knowing that it could be seven years or more before Jesus returns.
Against this objection, however, is the fact that the entire point of Jesus’ Olivet Discourse was to insure that His disciples would be ready for His return at or near the end of the Tribulation, and He revealed to them numerous signs that would precede His coming. Why is the Olivet Discourse punctuated with so many admonitions to be ready and to stay alert even when Jesus knew that His return had to be at least several years away from the time He originally spoke those words? Apparently Jesus believed that Christians need to be ready and stay alert even if His return is still years away. The apostles who in their letters admonished believers to be ready and stay alert for Jesus’ coming were only imitating Jesus Himself.
Additionally, those who believe that it is only a pre-tribulation Rapture that justifies any admonitions to stay ready have another problem. According to them, Christ’s first return precedes the end of the Tribulation by seven years. So Jesus’ first alleged return really can’t happen at just any time–it must happen exactly seven years before the end of the Tribulation. Thus in reality, there is no need to expect that Jesus will return until world events are in place to begin the seven years of Tribulation, events that can certainly be anticipated and ascertained.
Most who subscribe to a pre-tribulation Rapture, if they are honest, will say that they know Jesus will not return today or tomorrow due to the political situation in the world. There are still prophesied events that must be fulfilled before the seven years of the Tribulation can begin. For example, as we will soon learn from the book of Daniel, the antichrist will make a covenant with Israel for seven years, and that will mark the beginning of the Tribulation. Thus the Rapture, if it occurs seven years before the end of the Tribulation, must occur when the antichrist makes his seven-year agreement with Israel. Until there is something on the political horizon that will make that scenario possible, there is no need for pre-tribulation Rapture theorists to expect that Jesus will return.
Moreover, for those pre-tribulation Rapture proponents who believe that Jesus will also return at the end of the Tribulation, that means the exact day of Jesus’ alleged second return could be calculated. Once the Rapture occurs, anyone could calculate what Jesus said only the Father knows by just counting ahead seven years.
Again, from what Jesus actually did say, He clearly did not want His return to be a complete surprise. In fact, He wanted it to be anticipated by certain events of the Tribulation. Simply put, Jesus did not want His disciples caught off guard, as would the world. He continued His Olivet Discourse:
“For the coming of the Son of Man will be just like the days of Noah. For as in those days which were before the flood they were eating and drinking, they were marrying and giving in marriage, until the day that Noah entered the ark, and they did not understand until the flood came and took them all away; so shall the coming of the Son of Man be. Then there shall be two men in the field; one will be taken, and one will be left. Two women will be grinding at the mill; one will be taken, and one will be left. Therefore be on the alert, for you do not know which day your Lord is coming. But be sure of this, that if the head of the house had known at what time of the night the thief was coming, he would have been on the alert and would not have allowed his house to be broken into. For this reason you be ready too; for the Son of Man is coming at an hour when you do not think He will” (Matt. 24:37-44)
Again, Jesus’ obvious concern was that His disciples be ready for His return. That, in fact, was the primary reason for everything He said before and after this point in the Olivet Discourse. His many admonitions for them to stay ready and alert are not so much of an indication that His return would be a complete surprise, but an indication of how difficult it will be under the adversity of the time to remain ready and alert. This being so, those who are expecting an any-time, pre-Tribulation Rapture, thinking they are more ready than other Christians, may actually not be ready for what they may well face. If they expect no tribulation and then find themselves in the midst of worldwide persecution under the reign of the antichrist, the temptation to fall away may overwhelm them. Better to be prepared for what Scripture actually teaches will occur.
And again, if you asked Peter, James or John when they could expect to see Jesus return, they would have told you of all the signs that Jesus told them would occur just prior to His return. They would not have expected to see Him before the tribulation period or the rise of the antichrist.
 It doesn’t really make any difference if the person who is suffering judgment in these examples is the one taken or the one left to remain, as if often debated. The point is that some will be ready for Christ’s return and some will not. Their readiness will determine their eternal destiny.