Angels often deliver messages to humans. Many times angels deliver these messages through dreams. One biblical example of a person being visited by an angel is when an angel visited Joseph telling him about the birth of Jesus.
Before Jesus Christ was born, before Joseph married or had intimate relations with one another Mary was found to be pregnant. Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost. Matt. 1:18 Joseph thought about having Mary put away privately because she was pregnant Then Joseph her husband, being a just man, and not willing to make her a public example, was minded to put her away privily. Matt. 1:19 An Angel delivers a message to Joseph in a dream Joseph had a dream and an Angel of the Lord spoke to him. The Angel told Joseph not to be afraid, to go ahead and marry the woman Mary because the baby she was carrying belonged to the Holy Ghost. But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost. Matt. 1:20 Angel tells Joseph to name the unborn child Jesus The Angel also told Joseph that this special child would save the Lord's people from their sins. And she shall bring forth a son, and thou shalt call his name Jesus: for he shall save his people from their sins. Matt. 1:21 The Angel gave Joseph this message to make sure that prophecy was fulfilled Now all this was done, that it might be fulfilled which was spoken of the Lord by the prophet, saying, Matt. 1:22 Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us. Matt. 1:23 Joseph woke up and did as the Angel had told him Then Joseph being raised from sleep did as the angel of the Lord had bidden him, and took unto him his wife: Matt. 1:24 Joseph did not have intimate relations with Mary until after the child was born and Joseph named the baby Jesus. And knew her not till she had brought forth her first-born son: and he called his name Jesus. Matt. 1:25 Refers to:
But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost. Matt. 1:20