Oh, this is a comforting word to a believing heart, for without Christ, man is subjected to many raging tyrants who are not kings but murderers, at whose hands he suffers great misery and fear. These are the devil, the flesh, the world, sin, also the law and eternal death, by all of which the troubled conscience is burdened, is under bondage, and lives in anguish. For where there is sin there is no clear conscience; where there is no clear conscience, there is a life of uncertainty and an unquenchable fear of death and hell in the presence of which no real joy can exist in the heart, as Lev. 26:36 says: “The sound of a driven leaf shall chase them.”
17. Where the heart receives the king with a firm faith, it is secure and does not fear sin, death, hell, nor any other evil; for he well knows and in no wise doubts that this king is the Lord of life and death, of sin and grace, of hell and heaven, and that all things are in his hand. For this reason he became our king and came down to us that he might deliver us from these tyrants and rule over us himself alone. Therefore he who is under this king cannot be harmed either by sin, death, hell, Satan, man or any other creature. As his king lives without sin and is blessed, so must he be kept forever without sin and death in living blessedness

Luther’s Postil; First Sunday of Advent. Matthew 21:1-9. Christ Enters Jerusalem, or Faith, Good Works and the Spiritual Meaning of this Gospel