Jesus' disciple Thomas is usually remembered as "doubting Thomas" for being the one who didn't believe Jesus was resurrected until actually seeing him.  But this disciple ended much better than he started - he dedicated the rest of his life to the Lord, and he went to Kerela, India where he was martyred and killed with a spear while building the Lord's church.  The place where he was killed is today called "Mount St Thomas" in Chennai, India.
There was one thing that Jesus said to him which is I think one of the most important lessons we can take for our personal life:
John 20:29 Jesus *said to him, "Because you have seen Me, have you believed? Blessed are they who did not see, and yet believed." 
"..Blessed are those who did not see, and yet believed.."
The challenged to myself was this: The most blessed ones on earth are the ones who trust completely in Him without “seeing.”  I was blessed to take this verse as an encouragement for myself:  that I'm blessed without seeing (without seeing answers to prayer, or understanding God's reasoning behind things), but still keep on trusting the Lord.  I'm blessed if I, without seeing the reason God allowed some difficult challenge, and without knowing the end goal or purpose - if I still clinging to the fact that God is complete love and His ways are perfect.  Those ones are the most blessed - to "not see" (to not understand, to not see the answer yet), but still cling on to hope and trust in God, without demanding from God that they have to "see" to believe.
Hebrews 11 speaks highly of the godly men and women in that chapter who clung to hope in the Lord even while not seeing the outcome:
“All these died in faith, without receiving the promises, but having seen them and having welcomed them from a distance, and having confessed that they were strangers and exiles on the earth.” ‭‭Hebrews‬ ‭11:13‬ ‭
There are going to be some things which God withholds from us or which He allows that we will not fully see the reasons for this side of eternity.  It may be tragedy, it may be a long lasting weight which we have to carry, and we wonder “why?”  But the Lord says:
“Blessed are those who don’t see and yet still believe.”
Job said great words of faith, in Job 13:15 "Though He slay me, yet will I trust in Him."
But few people live such a life - where they can be slayed by God under such long lasting suffering, and still remain faithful.  They can confess:
"Lord you are good - I don't know why all these things are happening, I don't need to know why.  I don’t need deliverance in my time.  You choose “if” and “when” any of that comes.  You can slay me under any circumstance, and I will still hope in you."
“Blessed is the man who trusts in the LORD And whose trust is the LORD.” ‭‭Jeremiah‬ ‭17:7‬ ‭
I was struck recently when I realized that so many testimonies of saints (outside of the Bible) who I've been blessed by the most had severe suffering in their life, or even lives which were cut very short.  Consider these names:
Madame Guyon, Hudson Taylor, Eric Liddell, Samuel Morris, Watchman Nee, John Bunyan, David Brainerd, Fanny Crosby
These were lives of radical, godly Spirit-filled saints, but if you read their lives you'll also see radical suffering.  Amazing!  I'm convinced that a large part of their life with God and their ministry WAS a product of their faithfulness in suffering, that brought them to amazing heights.  Even many of the saints which we think didn't have as much suffering I'm sure had so much secret suffering.  And even if we do not suffer to the extent of them we can still be faithful and reach amazing heights in Jesus through our suffering - whatever it consists of (everyone has their own cross to bear, and it's different than others - uniquely designed for us).
Sometimes I picture of millions of people bowing before God in Heaven on the last day - the Bible says “every knee will bow”.  I think that means that even the worst, wicked unbeliever who hated God will fall down the day they see Him.  Everyone will bow that day and confess Jesus is Lord.
But God can get that glory now if a humble one who bows here on this earth before Him in their heart, saying "Lord, your will be done", while not seeing the outcome of things. They “bow their knee” by submitting to the circumstances God chose for them.
A humble struggling mother at home, a bullied child at school who prays to ask God for help and courage, a man persecuted and forsaken by his relatives and close family for his faith and finding his refuge in Jesus, saying “your will be done, only give me the grace for this.”
Clinging to the Father who allowed it..
That is beauty!
The life of the Apostle Thomas gives us hope that, in the past we may have been full of doubts, and complaints - endless cries that the Lord would "SHOW" us (show us an answer to prayer, or understand the reason for our suffering) so that we could trust and believe.  But the Lord can deliver us from that giant of unbelief.  Thomas ended well.  He was like Abraham - who started out trying to move God's hand by having a child (fixing the problem) with his own power.  To surrender completely to the Lord's will and timing, and trusting.
I trust the Lord will help me to be at rest more and more, even when there’s no end of my “not seeing” in sight for months, years or even many decades.  The Lord in the midst can make us the most blessed (blessed means happy!) people on earth, not when we finally “see”, but during our time of not seeing.
This is a privilege we only get here on this earth - we can only glorify God in this way during our few days on earth, since there is no suffering in Heaven.  At all costs - learn the “song of heaven” (praise) while you're here on this earth.  Sing to the Lord often in the midst of suffering: "You do all things well!"  God will be more glorified through that than through any number of ministry acts of service, and you will be most blessed through that, to learn that song, than through any number of answered "self" prayers.
I remember many years ago I heard a story of a woman who was suffering deeply - I forgot the reason.  It may have been her child was very sick or something serious to that effect.  My understanding is she was struggling in deeply her faith.  Someone said to her something that challenged her.  They said something to the effect of, "In the way you respond to this situation - you are choosing your destiny."
That story always stuck with me since I heard it, and challenged and encouraged me.  And I believe what this person told her is true:
Mat 9:29  Then He touched their eyes, saying, "It shall be done to you according to your faith." 
The way we respond to the hardship and struggle of life, when we don't see the reason, and don't see that outcome - the way we respond to it and trust that God is still perfect love, and choose to surrender and rest in Him, even before we "see" - that's a good indicator of what we ultimately will become.