Therefore exhort one another, and build each other up, even as you also do.

 Many of the most terrible pictures in the Old Testament are of the Day of the Lord ( Isaiah 22:5; Isaiah 13:9; Zephaniah 1:14-16; Amos 5:18; Jeremiah 30:7; Malachi 4:1; Joel 2:31). Its main characteristics were as follows. (i) It would come suddenly and unexpectedly. (ii) It would involve a cosmic upheaval in which the universe was shaken to its very foundations. (iii) It would be a time of judgment. 