Messenger

Isaiah 6:8 (The Prophet Isaiah as God's Messenger)
"Then I heard the voice of the Lord saying, 'Whom shall I send? And who will go for us?' And I said, 'Here am I. Send me!'"

Malachi 3:1 (The Messenger of the Covenant)
"I will send my messenger, who will prepare the way before me. Then suddenly the Lord you are seeking will come to his temple; the messenger of the covenant, whom you desire, will come,' says the Lord Almighty."

2 Corinthians 5:20
"We are therefore Christ’s ambassadors, as though God were making his appeal through us. We implore you on Christ’s behalf: Be reconciled to God."

John 1:6-7 (John the Baptist as a Messenger)
"There was a man sent from God whose name was John. He came as a witness to testify concerning that light, so that through him all might believe."

Mary

Luke 1:26-38 (The Annunciation)
"In the sixth month of Elizabeth’s pregnancy, God sent the angel Gabriel to Nazareth, a town in Galilee, to a virgin pledged to be married to a man named Joseph, a descendant of David. The virgin’s name was Mary. The angel went to her and said, 'Greetings, you who are highly favored! The Lord is with you.' ... 'Do not be afraid, Mary; you have found favor with God. You will conceive and give birth to a son, and you are to call him Jesus.'"

Luke 1:39-45 (Mary Visits Elizabeth)
"At that time Mary got ready and hurried to a town in the hill country of Judea, where she entered Zechariah’s home and greeted Elizabeth. When Elizabeth heard Mary’s greeting, the baby leaped in her womb, and Elizabeth was filled with the Holy Spirit. In a loud voice she exclaimed: 'Blessed are you among women, and blessed is the child you will bear!'"