God spoke to many people in dreams.

Abimelech (Genesis 20)
Jacob (Genesis 28)
Laban (Genesis 31)
Joseph (Genesis 37)
The cupbearer and baker to the king (Genesis 40)
Pharaoh (Genesis 41)
Solomon (1 Kings 3)
Nebuchadnezzar (Daniel 2)
Daniel (Daniel 7)
Joseph (Matthew 1)
The Wise Men (Matthew 2)
Pilate’s Wife (Matthew 27)

Dreams are a powerful tool to get people’s undivided attention or to trouble them with disturbing thoughts.

Then the LORD came down in a pillar of cloud; he stood at the entrance to the Tent and summoned Aaron and Miriam. When both of them stepped forward, he said, “Listen to my words:
“When a prophet of the LORD is among you,
I reveal myself to him in visions,
I speak to him in dreams." Numbers 12:5-6

While God uses dreams to speak, not every dream is from God.

If a prophet, or one who foretells by dreams, appears among you and announces to you a miraculous sign or wonder, and if the sign or wonder of which he has spoken takes place, and he says, “Let us follow other gods” (gods you have not known) “and let us worship them,” you must not listen to the words of that prophet or dreamer. The LORD your God is testing you to find out whether you love him with all your heart and with all your soul. Deuteronomy 13:1-3

We have to discern whether the dream is from God or a product of our imagination. If it lines up with scripture and it comes true, then we know it is from God.

This is a very fuzzy subject. I know people who have had dreams that came true. However, millions of dreams happen every night—some dreams we know of, most we don’t. Many of those don’t come true (and maybe for good reason since they feature us in our pajamas walking the halls of school).

Which dreams are from God and which are products of human brain activity? We have to discern them wisely. God uses prayer and scripture to speak to us more efficiently.