Behold, I am the handmaid of the Lord. May it be done to me according to your word.  Mary and St. Juan Diego probably never imagined that God would give them a major role to play in his plan of salvation.   Neither of them had any special training or standing in society.   But look what a difference they made. They changed history! Mary was a young girl from a poor family living in the backwater town of Nazareth.   On the day the angel Gabriel...