New World Encyclopedia online article:
Her life experience made her an advocate of the Christian Pre-millennialist view of a Post Tribulation Resurrection-Rapture.
Her own experience with the Nazis combined with what happened to Chinese Christians in 1949 as Mao Tse Tung was bringing China into communism led her to speak out about the Pre-Tribulation Rapture doctrine taught by some Christians.
In a letter she wrote in 1974 entitled "Prepared for the Coming Tribulation" she wrote:
There are some among us teaching there will be no tribulation, that the Christians will be able to escape all this. These are the false teachers that Jesus was warning us to expect in the latter days. Most of them have little knowledge of what is already going on across the world. I have been in countries where the saints are already suffering terrible persecution…
In America, the churches sing, "Let the congregation escape tribulation", but in China and Africa the tribulation has already arrived. This last year alone more than two hundred thousand Christians were martyred in Africa. Now things like that never get into the newspapers because they cause bad political relations. But I know. I have been there. We need to think about that when we sit down in our nice houses with our nice clothes to eat our steak dinners. Many, many members of the Body of Christ are being tortured to death at this very moment, yet we continue right on as though we are all going to escape the tribulation.
I think she goes too far in calling pre-trib teachers the false teachers Jesus warned about. I cite this for her perspective. I've come across this idea before, that many Christians throughout the world believe they are already in the Great Tribulation.