In the Christmas narratives, there are several "fear not's."
1. The "fear not" of salvation: "And the angel said unto them, Fear not: for, behold, I bring you good tidings...which shall be to all people. For unto you is born this day in the city of David a Savior, which is Christ the Lord" (Luke 2:10>, 11>).
2. The "fear not" of the humanly impossible: "Fear not, Mary,
the Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee:
For with God nothing shall be impossible" (Luke 1:30>, 35>, 37>).
3. The "fear not" of unanswered prayer: "Fear not, Zacharias: for thy prayer is heard; and thy wife Elisabeth shall bear thee a son, and thou shalt call his name John" (Luke 1:13>).
4. The "fear not" of immediate obedience: "Joseph, thou son of David, fear not to take unto thee Mary thy wife.
did as the angel of the Lord had bidden him" (Matthew 1:20>, 24> NPS)