Passage
And thou shalt have joy and gladness: and many shall rejoice in his nativity.
And thou shalt have joy and gladness: and many shall rejoice in his nativity.
Luke 1:12 And Zachary seeing him, was troubled: and fear fell upon him.
Luke 1:13 But the angel said to him: Fear not, Zachary, for thy prayer is heard: and thy wife Elizabeth shall bear thee a son. And thou shalt call his name John.
Luke 1:14 And thou shalt have joy and gladness: and many shall rejoice in his nativity.
Luke 1:15 For he shall be great before the Lord and shall drink no wine nor strong drink: and he shall be filled with the Holy Ghost, even from his mother's womb.
Luke 1:16 And he shall convert many of the children of Israel to the Lord their God.
The verse centers on "thou", "shalt", "gladness", "shall", "rejoice", and "nativity". It is saying that the verse draws attention to "thou" and "shalt", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 13's "But the angel said to him Fear..." into verse 15's "For he shall be great before the...", so "thou" and "shalt" belong inside that flow. In Luke context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "thou" and "shalt" with trust shaped by these words, not by a vague optimism outside the passage.