Before marrying, Mary had a baby. And, even though Joseph originally planned to marry her, he now planned to send Mary away secretly. But an angel told Joseph to take Mary as his wife because it is God's miracle. He said, this baby boy would save people from their sins. God planned to do what He promised: a virgin will be with a child named "God with us". So, Joseph obeyed God. An angel came to Mary too. The angel, Gabriel said that Mary would receive God's grace and she would have a baby. And this baby would be king forever. This would be a miracle. Mary said yes!