Luke 1:17-19

17 and he shall go before him in the spirit and virtue of Elijah; and he shall turn the hearts of the fathers into the sons, and men out of belief, [or that believe not], to the prudence of just men, to make ready a perfect people to the Lord.

18 And Zechariah said to the angel, Whereof shall I know this? for I am old, and my wife hath gone far in her days.

19 And the angel answered, and said to him, For I am Gabriel, that stand nigh before God; and I am sent to thee to speak, and to evangelize [or to tell] to thee these things.