The way of faith often crosses perpendicular to the interventions of God. Paul said in 2 Cor. 5:7, "For we walk by faith, not by sight:" Faith consists of counting God accurate in His statements, good in His actions, and righteous in His judgments. Faith therefore involves trusting God to keep His promises. This trust is by nature a trust whether or not one sees the one who promised. It is as if I answered the door one day to be greeted by a lawyer who announces a rich uncle has died and left his inheritance to his only surviving relative: me. My choices at that point are to believe the lawyer or not. If I believe the lawyer, I will invite him in for tea or coffee to discuss the matter. If I disbelieved him, he will likely have the door closed in his face. In either case, I never do get to see the uncle in question.
God's interventions both in history and in my life operate so differently from faith as to almost be an antithesis to faith. When God sent Gabriel to Zachariah the high priest, there was no question of Zacharias' faith in God:
There was in the days of Herod, the king of Judaea, a certain priest named Zacharias, of the course of Abia: and his wife [was] of the daughters of Aaron, and her name [was] Elisabeth. And they were both righteous before God, walking in all the commandments and ordinances of the Lord blameless (Luke 1:5-6).
Zechariah must have already demonstrated his faithfulness to become high priest. In the faithful discharge of his duty, an angel of God came to him, not to cause faith, nor even really to encourage it (though he did expand it) but to answer the faith Zachariah and Elisabeth already had in Yahweh:
And they had no child, because that Elisabeth was barren, and they both were [now] well stricken in years (Luke 1:7).
When the angel appeared, the nation of Israel more or less believed the Scriptures as I do now, as they were available in the Old Testament. Most of the prophecies (pro...