And some who have understanding will fall victim to persecution. In this way, they will be tested and cleansed and made pure until the time of the end, for the appointed time is still to come --------- Many will be purified, cleansed, and refined by these trials. But the wicked will continue in their wickedness, and none of them will understand. Only those who are wise will understand.
Daniel 11:35,12:10
Not all believers will be raptured - only those who are filled with The Spirit and have made themselves ready and Jesus knows who they are.
If not found ready when He comes for them - they will fall victim (as a thief in the night comes) into Tribulation to be Purified and made ready.
If you are wise you will understand this.