What are some reasons why God might communicate in a dream?

Acts 16:9-10That night Paul had a vision: A man from Macedonia in northern Greece was standing there, pleading with him, “Come over to Macedonia and help us!” So we decided to leave for Macedonia at once, having concluded that God was calling us to preach the Good News there.

God could use a dream to call you to a unique assignment. The Holy Spirit had told Paul and his companions not to go to Asia or Bithynia (Acts 16:6-7). They were probably confused as to where they were to go to preach the Good News. It was clear from this vision that the Holy Spirit was guiding them to Macedonia, where they would be more productive in the Lord’s work.

Genesis 28:13-15At the top of the stairway stood the Lord, and he said, “I am the Lord, the God of your grandfather Abraham, and the God of your father, Isaac. The ground you are lying on belongs to you. I am giving it to you and your descendants. Your descendants will be as numerous as the dust of the earth! They will spread out in all directions—to the west and the east, to the north and the south. And all the families of the earth will be blessed through you and your descendants. What’s more, I am with you, and I will protect you wherever you go. One day I will bring you back to this land. I will not leave you until I have finished giving you everything I have promised you.”

God could use a dream to encourage you, as he did Jacob, and remind you of his presence and promises. In this passage, Jacob’s dream contained no new revelation from God, but confirmed important knowledge.