People will realize that he is a prophet. This can be stated in active form. AT: "people will know that you are a prophet" (See: [[rc://en/ta/man/translate/figs-activepassive]])
Before the Lord comes, he will go and announce to the people that the Lord will come to them. See how you translated this in [Luke 1:17](./16.md).
# the face of the Lord
"the face of" someone can be an idiom that refers to the that person's presence. It is sometimes omitted in translation. AT: "the Lord" See how you translated this in [Luke 1:17](./16.md). (See: [[rc://en/ta/man/translate/figs-idiom]])
This is a metaphor that means that John will prepare the people to listen to and believe the Lord's message. (See: [[rc://en/ta/man/translate/figs-metaphor]])
# to give knowledge of salvation ... by the forgiveness of their sins
The phrase "give knowledge" is a metaphor for teaching. The abstract nouns "salvation" and "forgiveness" can be expressed with the verbs "save" and "forgive." AT: "to teach his people salvation through the forgiveness of their sins" or "to teach his people how God saves people by forgiving their sins" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-abstractnouns]])