It is not of God to think legalistically there is only one rapture or resurrection. God reveals to us at least 12 raptures and/or resurrections. We may know the specific reason for these various raptures. Believers in the last days must pay attention to 3 essentials: (1) eternal life, (2) rapture, and (3) reward. Thank God, He has already provided the first essential. He has chosen us before the foundation of the world that through the death of Christ we should receive eternal life. The other essentials are something required of us.
I see 12 raptures in the Bible.
1) Enoch and Elijah (representing readied overcomers and first rapture);
2) Christ;
3) Those out of the grave at Christ's death (companion firstfruits);
4) Lazarus raised from the dead, as well as, the 12 year old girl who was only asleep (Matt. 9.18-26) - we are only appointed once to die so then comes rapture;
5) First rapture (Rev. 3.10, Luke 21.36, Matt. 24.37,40-41,42) at Rev. 7.9 before the trumpets of the Tribulation (Rev. 8ff) - firstfruits before the first month of Tribulation signified by the two wave loaves (could signify the first rapture and the harvest rapture or the rapture of those who are saved among both the Jews and Gentiles) in Lev. 23 at Pentecost. These two wave points also can typify from the time of Pentecost to the first rapture based on readiness, watchfulness, patience and holiness in our manner of life;
6) Philip the evangelist, who was raptured while at work (a type) away to Caesarea - reward is related to our work. Rapture and reward are interrelated, such as in the case of Philip;
7) Many martyrs raptured separately and individually during Tribulation (many) like the Two Witnesses;
8) Two Witnesses (Enoch and Elijah) raptured at the end of the 42 months of the Great Tribulation which is 1260th+3.5 days into it (the gleaning period of 30 days is to the 1290th day-this 30 days is for judgment by Christ when He is on earth with his sickle and divides the good and bad nations as sheep from goats in Matt. 13 and Matt. 25.31-46);
9) The 7th trumpet resurrection and rapture (final harvest of the last week in Daniel 9) which is pre-wrath at the start of the 19th month of Great Tribulation (1 Thess. 4.15-17, 1 Cor. 15.23 and Rev. 14.14-16). The last trumpet or 3rd woe of the 7 bowls lasts 24 months from the 19th to the 42nd month;
10) Those raptured after the 7th trumpet resurrection from the 19th month to the 24th month of Great Tribulation are gleaned like in any field(various fragmentary raptures).**
11) Last Revolt at the end of millennial kingdom, there is the resurrection and rapture of the unsaved from the bad side of Hades (where the rich man is) to be judged and cast into hell;
12) Last Revolt end of the millennium rapture of the saved from the good side of Hades (Abraham's bosom, sometimes called paradise below) for those who died in the 1000 years.
It is very special to note that anyone who is resurrected is also to be raptured, but not all those who are raptured were resurrected, since they did not die. Rev. 20.4 refers to the first resurrection overcomers who receive the reward of reigning during the millennial kingdom.