What does Luke 1:75 mean?

God made promises to patriarchs of Israel like Abraham (Genesis 22:16–18). Later generations saw God working to assure these prophecies would come true (Exodus 6:8). Zechariah, a priest (Luke 1:5, 67–68) is celebrating fulfilled prophecy, seen in the birth of his son, John (Luke 1:13–17, 57; Isaiah 40:3). He is also anticipating the birth of Jesus Christ (Luke 1:31–33), the Messiah guaranteed in other Old Testament prophecies (Isaiah 9:6–7).

One of the end results of the Messiah's arrival would be the end of sin, evil, and fear (Luke 1:73–74; Zephaniah 3:14–17). The first arrival of Jesus on earth would establish human salvation, and the freedom from the eternal penalty of sin (Hebrews 6:17–20). His second coming will lead to the complete defeat of death and wickedness (Revelation 19:11–15; 21:1–5). This will allow those saved by God to be freed from the slavery of sin (Romans 7:14–20), completely and eternally (1 John 3:2; 1 Corinthians 15:52–57).