I part company with George Mueller because George Mueller rejected Darby's pretrib rapture. I reject pretrib onlyism, because I believe in partial rapture, but George Mueller is wrong too. Mueller doesn't teach partial rapture.

George Mueller said: "My brother I am a constant reader of the Bible, and I soon found out what I was taught to believe (by Darby's doctrine) did not always agree with what my Bible said. I came to see I must either part company with what John Darby, or my precious Bible, and I chose to cling to my Bible and part from Mr. Darby." - George Mueller, a contemporary and one time supporter of John Nelson Darby quoted by Robert Cameron, Scriptural Truth About the Lord's Return, pp. 146-7.

"Because thou didst keep the word of my patience, I also will keep thee from the hour of trial, that hour which is to come upon the whole world, to try them that dwell upon the earth" (Rev. 3.10).

Do all Christians do this? No. Therefore not all Christians will escape the Tribulation, but must pass through the time of testing and be raptured pre-wrath (Rev. 11.15, 15.2) before the bowls of the 7th trumpet.