Last week, I had the chance to read the very short book called Tzipita Lishua, written by the Hafetz Hayim - R' Yisrael Meir Kagan, ZaTza"L. It contains 3 chapters:
Chapter 1 discusses the apparent contradiction between the verses in Parshat Nitzavim which talk about the Geula coming from Teshuva - and the Gemaras in Sanhedrin and Sota, which talk about moral decay preceding the Geula. The Hafetz Hayim seems to say that both are necessary.
Chapter 2 discusses not giving up hope on the Geula happening despite trials and tribulations that may come, whether physical or spiritual.
Chapter 3 discusses the necessity of Torah scholars, but Kohanim in particular, to know the laws of Kodashim and of the Beit Hamikdash since it would not be good to be unprepared for a sudden Geula.
May we learn those laws and merit the Geula - Bimhera Veyamenu, Amen.