Corrie Ten Boom's letter is an excellent example of what a mature Christian ought to be..... conformed to the image of Christ by participating in "the fellowship of His suffering" ( Philippians 2: 10 ). I couldn't agree with her more, and Corrie is one of my all-time favorites among Christian authors [ The Hiding Place ] and saints.

With that being said, I would like to add one comment. While it is true that we must all suffer in this world
( " in this world ye shall have tribulation" ) ,
it is not true that we will all go through the Great Tribulation. We do not suffer for sufferings' sake.
We are part of a big plan of God. Some of the Church will be part of that song she mentioned:
" let Thy congregation escape tribulation" by going to be with our Lord at the Rapture, which we believe will happen soon.

Should not all Christians put forth the Blessed Hope of the Rapture before the last 3 and 1/2 years of this age 
If not, then they have missed an opportunity to bless the brethren in obedience to 1 Thessalonians 4: 18
"wherefore comfort one another with these words". 

When the Rapture did not take place at midnight on the Millennium, many Christians despaired of any pre-Rapture at all and resigned themselves to a worst-case scenario : end-time Rapture ( although I can't see why anyone would be comforted by knowing they would suffer the 7 vials of end-time G-trib.)

Yes, it is true that we suffer in this lifetime, and that some people suffer more than others. And it is also true that some people never seem to suffer at all.

Let me give an illustration:

Betsy Ten Boom died in the concentration camp. 
She would exemplify having gone through the Great Tribulation ( worst case scenario ).

Corrie Ten Boom suffered in concentration camps for 3/4 of a year and then miraculously was released.
She would exemplify a partial time of Great Tribulation ( like those who await the pre-wrath Rapture).

Nollie Ten Boom never went to a concentration camp. She would exemplify those who are raptured before the Great Tribulation begins. She did go to prison for a few weeks ( "In this world ye shall have tribulation" ) but she escaped
the horrors of a concentration camp.

We see from the above that the three Ten Boom women are a type of what is to come.

Nollie typifies those who will escape the last 3 and 1/2 years of the Great Tribulation by going in the Midnight Rapture. ( Matthew 25 : 1--13  )

Corrie typifies those who will be raptured later, having gone through part of the Great Trib , yet being caught up at the time of the pre-wrath Rapture ( before the 7 vials are poured out ) or what Jesus referred to as the "Cockcrowing Rapture." Mark 13: 35 and  Rev. 16 : 15

Betsy Ten Boom drank the full cup of suffering unto death and typifies those who will be transformed into their glorified bodies on the Last Day .. or that is to say, those who die during the Great Tribulation. ( Rev. 7: 14-17).
In that sense Betsy truly was healed,  where she thirsted and hungered and cried no more.

Jesus tells us in John 14:16 that the Holy Spirit is "our Comforter". He comforts us whenever we go through sorrows, trials and persecutions and even executions. He comforts us in sicknesses. And He comforts the Bride at the rapture ..."the Spirit and the Bride say "Come".

" And at Midnight the cry arose ... and those that were ready went in with Him to the marriage and the door was shut".
Matthew 25: 1--13