The angel said to her, ‘Mary, do not be afraid; you have won God’s favour. Look! You are to conceive in your womb and bear a son, and you must name him Jesus. He will be great and will be called Son of the Most High. The Lord God will give him the throne of his ancestor David; he will rule over the House of Jacob for ever and his reign will have no end.’ Mary said to the angel, ‘But how can this come about, since I have no knowledge of man?’ The angel answered, ‘The Holy Spirit will come upon you, and the power of the Most High will cover you with its shadow. And so the child will be holy and will be called Son of God. 
LUKE 1:30-35