“Alas, you who are longing for the day of the LORD, For what purpose will the day of the LORD be to you? It will be darkness and not light... even gloom with no brightness in it.”
‭‭Amos‬ ‭5:18, 20‬ ‭NASB‬‬
This is a very sobering verse for those of us who believe that we are longing for the day of the Lord. The Holy Spirit is saying that it is possible to think that I long for His return, and yet for His return to be other than I expected. Lest we dismiss this as an irrelevant passage from the Old Testament, there’s a similar truth expressed in the New Testament as well:
“But to the degree that you share the sufferings of Christ, keep on rejoicing, so that also at the revelation of His glory you may rejoice with exultation.”
‭‭1 Peter‬ ‭4:13‬ ‭NASB‬‬
The Holy Spirit says here as well - even in the New Testament - that it is not guaranteed that we will be found rejoicing when Christ returns, as we might expect. But this verse also sheds light on how to keep from being surprised in that day. Who will rejoice with exultation at the revelation of Christ’s glory? Those who have learned to rejoice in suffering now. And for whom will the day of the Lord be “darkness and not light”? Those who have not learned to rejoice in suffering now. 
If I want to know whether I will be found rejoicing when Christ returns, I just need to examine how I respond to suffering now. I don’t want to delude myself: no matter what I might think of my “hope” in His return, if I do not rejoice in suffering now, I will not rejoice with exultation when He appears in glory. 
The Story of Gertrude Chambers
I read a story recently that really touched my heart. Most of us know that Oswald Chambers’ devotional classic, My Utmost for His Highest, was published after his death. He died as a young man of 43 of peritonitis as an army chaplain in World War I, and his wife collected, edited and published the collection many years later. It and many other of his posthumously published books have blessed many millions of people thanks to his wife’s diligence to record many of his messages, etc. During the rest of her life, she wrote 31 books’ worth of her husbands’ sermons and lectures. What a suitable helper God sovereignly appointed for his young servant, Oswald Chambers. What many don’t know is how He prepared the helper. 
When Gertrude Hobbs was a small child, she was diagnosed with chronic bronchitis, and unable to go to school for several months each year. And then, when she recovered from her sickness, her parents decided to keep her at home to care for her ailing grandmother, because she had already missed so much school already. Despite never going to school, for whatever reason, Gertrude had it in her heart that she wanted to be the Secretary to the Prime Minister of England, and so she decided to take a correspondence course in shorthand, a method for quickly taking dictation long before typewriters  or computers were invented. 
During the course of her self-initiated studies, she became very accomplished at shorthand, eventually able to transcribe approximately 250 words per minute, and she become a dependable secretary for barristers and junior statesmen. 
And then she married a young man named Oswald Chambers. He was not particularly famous, but he was a faithful minister of the Word, and the Lord was clearly with him, blessing his modest preaching and teaching responsibilities. Early in their marriage, Gertrude felt a burden placed upon her heart to “write down everything he says.” She began accompanying him to classes, lectures, sermons, and Bible studies, sitting in the back of the auditorium and diligently capturing every word in the shorthand she had learned while convalescing at home instead of being in school. 
And then the War began, Oswald felt a tremendous burden to minister to soldiers on the front lines in Egypt, so he became a chaplain and administered a station for the YMCA in Cairo. His work was blessed of the Lord, being used to encourage many dejected young men at a very low point in their lives. And then Oswald died very unexpectedly of undiagnosed appendicitis. He was only 43, and he and Gertrude had only been married for seven years. 
Gertrude, now caring for her four year old daughter alone, immediately took up Oswald’s responsibilities at the base. Her daughter later recounted, “Nobody ever saw my mother crying. She always believed that what He allowed to happen and what He sent meant that He was there anyway all the time. She was never sorry or sad, feeling that God had made a mistake because my father was at the beginning of his life.” As she was going through her things, Gertrude realized that over a few short years, she had accumulated a cabin trunk’s worth of shorthand transcripts, and only in time did she come to see it as her life’s work to edit and publish these books. She often did this while working 12 hours a day providing for herself and her daughter, as Oswald had always believed in trusting the Lord alone for all their needs, and that “one had to be poured out wine in order to bless others.”
This is the wondrous story of the Lord’s preparation of the suitable helper He appointed for Oswald Chambers and his ministry. What a path of preparation. Surely, she could look back over all of her life and say, “God’s ways are perfect.” I believe she can relate to Joseph, who could look back over a life filled with troughs and valleys, of being mistreated and forgotten, and say, “What I was tempted to see as evil, God meant not only for my good, but for the salvation of many people” (Genesis 50:20). 
Reflecting on her story, I was imagining how heartbreaking it must have been for her parents to see their child sick, and how much they must have been tempted to complain and even despair at her condition and its implications for her future. I can only imagine how I might feel if one of my daughters was incapacitated from schooling due to sickness. And yet we see that it was this path - the path her parents surely never would have chosen - that was the essential preparation for the unique ministry God that had for her and for her husband. 
We know that one day, in the final day, it will be perfectly seen how all of God’s dealings - not just with Gertrude and Oswald - but with every single person, are perfect and just. Every person will be able to look back on their life from the vantage point of eternity and say, “He did all things well.” But as Christians, we don’t have to wait for that day! We can say that now, in the face of every difficulty, full of faith that we will see how each part of our life is perfectly designed to accomplish His most perfect plan for us. Indeed, we can boldly claim the promise of Romans 8:28 in the face of every fear, every setback, and every disappointment. 
On the day Christ returns, when His perfect dealings are revealed in all their splendor, who will have reason to “rejoice with exultation”? It will be the ones who knew it all along, and who rejoiced in the midst of their sufferings, full of faith that even disappointments are perfect in His plan. I tremble at the thought that there might be some circumstance or dealing that has found me refusing to rejoice. And fear to think of the day His perfect wisdom is made known, that I might have cause not for rejoicing, but for regret that I wasted any time in complaining, in grumbling, in anxiously looking about me, etc. What a shame it will be if I only realize then how perfectly every difficulty served to accomplish His glorious purpose, and wish I could go back and live my life again, with the knowledge that every trial really is perfectly fitted into His wondrous design.  
No matter what I think about how I will respond when Christ returns, or what my grounds for thinking I’ll rejoice at His return are, the Bible tells me clearly how I can know whether I will rejoice: if I “keep on rejoicing” now, in the midst of suffering, only then will I rejoice when He returns in His glory (1 Peter 4:13). Even Jesus was diligent to praise the Lord on the cross (Psalm 22:22-28). If I likewise humble myself under God’s training and refining, and choose to rejoice in all circumstances, then I can be 100% certain that I will have cause to rejoice with exultation upon His return. 
But the warning for me is this: don’t comfort myself with thoughts of Christ’s return if I’m not rejoicing in the midst of suffering. It says in Amos that those people for whom the day of the Lord would be “gloom with no brightness in it” were the same people who were playing harps and singing songs and hosting festivals and even calling very solemn assemblies, indeed, they were “longing for the day of the Lord” (Amos 5:19-23, the passage surrounding the verse at the beginning of this post). In short, they were like many Christians today, busy with lots of religious seeming activity. No matter. Confidence based on such religious activity is a complete delusion. It was for these harp-playing, hymn-singing, festival-hosting, solemn-assembly-attending, that-day-longing religious folk that the Holy Spirit said, the day of the Lord will be “gloom with no brightness in it.”
I want to take the command to rejoice always (1 Thessalonians 5:16) very seriously, not as a “nice to have,” but as an absolute must have. I want to take courage from the Lord’s dealings with people like Gertrude Chambers, and be constantly reminded of this truth: 
Rejoicing now - on this day - is the indispensable pre-requisite to rejoicing on that day, when Christ returns.