I would like to share a book with you called אחרית כראשית by Rav Aryeh Shapira. The book quotes from Ramchal and the Gra and speaks extensively about the stages leading up to Geulah. The book is written in Hebrew and brings the original sources, and I will translate to the best of my ability be'H.
Our tradition teaches that the redemption of the Jewish people is not something that occurs all at once, but rather it comes slowly, stage by stage, step by step, like the sky slowly brightening as the morning dawns.
This is stated by the sages in Medrash Tanchuma at the beginning of Devarim:
The passuk says (Yeshaya 35) ישושום מדבר וציה [ותגל ערבה ותפרח כחבצלת. פרוח תפרח ותגל אף גילת ורנן כבוד הלבנון ניתן לה הדר הכרמל והשרון המה יראו כבוד ה' הדר אלוקינו] כו - "The desolate desert will rejoice. [And the willow will sprout like a lily. It will blossom and rejoice greatly and sing; The honor of Lebanon will be hers, the beauty of Carmel and the Sharon. They will see the honor of Hashem, the beauty of our God.]" Why is it written this way? To teach you that at the time Hashem reveals his Divine Presence upon the people of Israel, He doesn't reveal it all at once, for they would not be able to receive that Good all at once, for if He would reveal the Good all at once they would all die. See what it says (ibid. 64) ומעולם לא שמעו לא האזינו עין לא ראה אלקים זולתך יעשה למחכה לו - "It was never heard or seen except by the Eye of Hashem - that which will be done for those who wait [for the Redemption]."
Let us learn from Yosef, when he revealed himself to his brothers after many years, he said to them, "I am Yosef your brother." They all died [of embarrassment] and could not respond. Certainly it would be so with Hashem. Rather, what does Hashem do? He reveals Himself bit by bit. At first, he makes the desert rejoice as it says ישושום מדבר וציה - "the desolate desert will rejoice," then the "willows rejoice and sprout like a lily." Then "it will blossom," and then the "honor of Lebanon will be hers." Finally "they will see the honor of Hashem, the beauty of our God."
The sages similarly said in the medrash Shocher Tov (end of chapter 19 of Tehillim), on the passuk, מגדיל ישועות מלכו ועושה חסד למשיחו - "He makes the salvations of His king great, and makes kindness for His anointed" :
One verse says מגדיל (He makes great), and one says מגדול (it is great). Rav Yuden said that this is because the Redemption of this nation will not occur all at once, but rather bit by bit. Thus the verse says מגדיל - He makes great - because it continuously grows before the people of Israel. This is necessary since they are currently entrenched in great difficulties, and if the redemption would come all at once, they would not be able to withstand the tremendous salvation that comes from amidst terrible suffering. Therefore it comes bit by bit, getting gradually stronger. For this reason the redemption is compared to the dawn, as the verse says (Yeshaya 58), אז יבקע כשחר אורך - "then Your Light will burst forth as the dawn." Why is it compared to dawn? For there is no greater darkness than the moment before morning.
To be continued...