Throughout the Old Testament many descriptions of the Day of the Lord are accompanied by the picture of a woman in labor. The Day of the Lord is the day when Jesus returns to earth to bring an end to the great war that threatens to annihilate mankind and to usher in His Millennial Kingdom. The following are references that include the phrase "woman in labor".

1) Psalms 48:6
2) Isaiah 13:8-9
3) Isaiah 21:2-9
4) Jeremiah 4:26-31
5) Jeremiah 6:22-24
6) Jeremiah 13:19-21
7) Jeremiah 22:2123
8) Jeremiah 30:6-7 (This passage points out that the Tribulation period will be for the Children of Israel and not for the Church.)
9) Jeremiah 48:40-43
10) Jeremiah 49:22-24
11) Jeremiah 50:41-43
12) Micah 4:9-12

The occasion of the Church meeting Jesus in the air is separate from the great Day of the Lord when He returns to end war and reign as Prince of Peace. The apostle Paul, in writing to the church at Thessalonica, is trying to comfort them and give them hope. Here he uses the picture of the woman in labor just as it was used in the Old Testament. The event he is discussing is the gathering of the Church to be with the Lord. Although it is unsaid in this passage, it is known that a pregnant woman will not be surprised by her labor pains. She does not know the day or the hour, but she does know about when labor pains should come. Likewise, the Church does not know the day or the hour, but will be expecting the "labor pains". In addition, why would the Hebrew writer instruct us to encourage each other "all the more as you see the Day approaching"? (Hebrews 10:25)

Twice in I Thessalonians 4:13-5:11 Paul says to encourage one another. If he was telling them that they would go through the Tribulation, that would not be very encouraging. He was encouraging the Church because the Church has hope. In Genesis 18:25 Abraham is pleading for the righteous in Sodom. In speaking to the Lord he says, "Far be it from you to do such a thing – to kill the righteous with the wicked, treating the righteous and the wicked alike." God does not change. He is the same today, tomorrow and forever. He will rescue the righteous from the Tribulation just as He rescued the righteous from Sodom. Praise His name!