Luke 1:18

Though Zacharias was righteous and holy, nevertheless, considering the extraordinary nature of the birth of a son, he did not easily believe.

He therefore introduces the doubt of the priest, when he says: And Zacharias said to the Angel: How shall I know this? that is, by what sign shall I be made certain? First Corinthians chapter one: "The Jews require signs." — Indeed note that some …

And Zacharias said to the angel, "How shall I know this? For I am an old man, and my wife is advanced in her days." Hesitating because of the magnitude of the promises, he seeks a sign by which he might be able to believe, …

As if he says, "If it were man who promised these miracles, one might with impunity demand a sign, but when an angel promises, it is then not right to doubt. It follows; And I am sent to speak to thee.

And Zacharias said unto the angel, whereby shall I know this?.... Notwithstanding such an appearance of an angel to him, which in those times was not so usual, and this in the holy place; and the things themselves which were told him, and these as the return of prayer; yet he distrusted, and wanted a sign, whereby he might know the truth of them, as the Jews were generally desirous of, and as the father of them was; who expressed himself in much such language, on a certain occasion, as this his son did; see Gen 15:

This was not a humble petition for the confirming of his faith, but a peevish objection against what was said to him as altogether incredible; as if he should say, "I can never be made to believe this." He could not but perceive that it was an angel that spoke to him; the message delivered, having reference to the Old-Testament prophecies, carried much of its own evidence along with it.

Whereby, &c.--Mary believed what was far harder without a sign. Abraham, though older, and doubtless Sarah, too, when the same promise was made to him, "staggered not at the promise of God through unbelief, but was strong in faith, giving glory to God." This was that in which Zacharias failed.

We see in this passage, the power of unbelief in a holy man. As righteous and holy as Zachariah was — the announcement of the angel appeared unbelievable to him. He could not think it possible that an old man like himself could have a son. "How shall I know this?" he says, "for I am an old man, and my wife well along in years." A well-instructed Jew, like Zachariah, ought not to have raised such a question. No doubt he was well acquainted with the Old Testament Scriptures. He ought to have remembered the astonishing births of Isaac , and Samson , and Samuel in old times. He ought to have remembered that what God has done once — He can do again; and that with Him, nothing is impossible. But he forgot all this. He thought of nothing but the arguments of mere human reasoning. In the same way, it often happens in religious matters, that where human reasoning begins — faith ends. Let us learn in wisdom from the fault of Zachariah. It is a fault to which God's people in every age have been sadly liable. The histories of Abraham, and Isaac, and Moses, and Hezekiah, and Jehoshaphat — will all show us that a true believer may sometimes be overtaken by unbelief . Unbelief is one of the first corruptions which came into man's heart in the day of the fall, when Eve believed the devil rather than God. Unbelief is one of the most deep-rooted sins by which a saint is plagued, and from which he is never entirely freed until he dies. Let us pray daily, "Lord increase my faith!" Let us not doubt that when God says a thing — that thing shall be fulfilled. We see furthermore, in these verses — the privilege and portion of God's angels. They carry messages to God's people. They enjoy God's immediate presence.

We see in this passage, the power of unbelief in a holy man. As righteous and holy as Zachariah was — the announcement of the angel appeared unbelievable to him. He could not think it possible that an old man like himself could have a son. "How shall I know this?" he says, "for I am an old man, and my wife well along in years." A well-instructed Jew, like Zachariah, ought not to have raised such a question. No doubt he was well acquainted with the Old Testament Scriptures.

ZACHARIAS and the Virgin Mary were both very dear to God and, therefore, highly honored and greatly favored. The points of likeness between them are many. They were both persons of eminent character, for Zacharias walked blameless in all the ordinances and commandments of the Lord and Mary was equally gracious and devout. They were both visited by an angel and were both favored with the prediction of a marvelous birth. Their answers to the angel are our two texts and, at first sight, they seem to be alike. One does not see much less of faith or of unbelief in the one than in the other at first reading them and, yet, Zacharias was blamed and chastened by being made dumb for a season. On the other hand, the Virgin was indulged with an explanation and was afterwards praised by the Holy Spirit who spoke through her cousin Elizabeth and said, "Blessed is she that believed: for there shall be a performance of those things which were told her from the Lord." It appears very clear, then, that God can see differences where we see none. Though two persons may act very much alike and from their lips may fall similar expressions, yet their temper and spirit may be widely different Where you and I would put them together and say, "They are alike," God sees a difference. While we judge sights and sounds, the Lord weighs the spirits. You must have noticed this in other parts of God's Word. I will give you two instances in the life of Abraham. Lot was commanded not to look towards Sodom, but his wife, after looking to Sodom, was turned into a pillar of salt. And yet that morning Abraham got up early to the place where he was known to meet with the Lord and it is recorded that he looked toward Sodom. The very thing which Lot must not do, Abraham may do.

Whereby shall I know this? - All things are possible to God: no natural impediment can have any power when God has declared he will accomplish his purpose. He has a right to be believed on his own word alone; and it is impious, when we are convinced that it is his word, to demand a sign or pledge for its fulfillment.

Whereby shall I know this? - The thing was improbable, and he desired “evidence” that it would take place. The testimony of an “angel,” and in such a place, should have been proof enough; but people are slow to believe the testimony of heavenly messengers. As a consequence of not believing, he was struck mute.