Isaiah 7:10-14 / Luke 1:26-38
We may have our questions about how God speaks to us.
And even if we believe that God does speak to us, the question is about how clearly we can understand what He wants and how certain we are that it is God who is speaking to us.
But that was not the case with king Ahaz in the 1st reading. The Lord God was telling him to ask for a sign in no uncertain terms.
Yet Ahaz refused to ask for a sign because he would rather trust in his allies than to trust in what God would do for him.
As for Mary, she was disturbed by the greeting of the angel Gabriel, and like any one of us, she would be not be able understand the message entirely, nor would she be certain that it was what God wants of her.
Mary did not ask for a sign, but God gave her a sign - her kinswoman Elizabeth, has in her old age, conceived a son, for nothing is impossible with God.
That was the sign that confirmed for her the message of the angel, and hence she accepted the will of God.
So if we are discerning what the will of God is for us and what He wants of us, let us ask for a sign, and it will be a sign that we will certainly understand.
And even if we didn't ask for a sign, God will also show us what He wants of us. For nothing is impossible to God.