Luke 1: In the sixth month the angel Gabriel was sent from God to a city of Galilee named Nazareth,  to a virgin betrothed to a man whose name was Joseph, of the house of David. And the virgin’s name was Mary.  And he came to her and said, “Greetings, O favored one, the Lord is with you!”  But she was greatly troubled at the saying, and tried to discern what sort of greeting this might be.  And the angel said to her, “Do not be afraid, Mary, for you have found favor with God.  And behold, you will conceive in your womb and bear a son, and you shall call his name Jesus.  He will be great and will be called the Son of the Most High. And the Lord God will give to him the throne of his father David,  and he will reign over the house of Jacob forever, and of his kingdom there will be no end.”
 And Mary said to the angel, “How will this be, since I am a virgin?”
Luke 1:34 – Mary said “How will this be…?” When Zechariah was told that he and Elizabeth were going to have a child he said “How shall I know this?” and he was struck dumb (and probably deaf too – see verse 62). When Mary asked her question there is no indication that Gabriel was the least bit upset. The reason? The difference between the questions is cavernous.
Zechariah basically says “I need some proof from you before I am going to believe that (see verse 18)”. His “how shall I know this” amounts to “prove it” or “why should I believe this?” It is a clear indication that he does not believe what Gabriel has said is going to happen.
Mary, on the other hand says “How can this be, since I am a virgin?” In the first place she is saying that the one thing for sure that is not going to happen is that she is going to lose her virginity. She seems to know that the conception is about to happen soon and the thought that she would engage in sexual activity with anyone, Joseph or not, is simply not on her radar. She knows that God will never give a message that will violate His already revealed Word. We could learn a lot from her in that alone. Think God wants you to do something? He will not call you to violate the Scriptures.
Secondly, she does not question the validity of what is to happen. She simply wants to know how. She knows that her God can do whatsoever He pleases, but she would like to know how it is that a virgin can get pregnant.
Christians legitimately engage in this all the time. We believe that all things work out for good, but we cannot for the life of us imagine how the crisis we are in at the moment can accomplish any good thing. To ask God to explain it to us is not wrong or an evidence of doubting what He has said. Mary is not saying “Yea, right, and how is that going to happen?” She is asking quite honestly, how this can be.
And Gabriel answers her. He tells her about the Holy Spirit overshadowing her and impregnating her. It is not a sin to not be able to figure out the workings of an incomprehensible God. But when we doubt what He says because it is beyond our understanding, as Zechariah did, we are in fact, claiming to know all there is to know. Since we cannot figure out what God is doing, then it must be that God is not doing it. This is pride gone mad. It is why Zechariah was disciplined.
Mary bowed to the sovereignty of God and simply asked how He was going to do this. May God grant us all a Mary like spirit and when we get some sort of answer from the Lord then let us say with her “let it be to me according to your word.” (Verse 38).