It might come as a shock to you but dove is usually associated with holiness, divinity, and celestial beings. Yes, this might be so true because the dove is the only bird associated with heavenly manifestation in the Bible. Come to think of it, the dove is a heavenly body because it's a bird, and it is associated with the sky.
Celestial beings and bodies are the angels, human spirit, holy spirit, heavenly bodies associated with divinity, such as the birds, sky, sun, moon, and stars. This place the dove in a holy ground or place. Judging by the Bible, Dove again is associated with Holiness and Divinity. Recall in the Bible, a dove appeared after Jesus Christ has been baptized.
This is the manifestation of Holiness, Divinity, and Celestial being in place. Going by the Bible chapter which says in the book of Matthew 3:16 "And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him."
This is pure holiness, the divinity in action and celestial being coming down from heaven in the form of a dove. Another point to note via this passage is that the spirit of God came down upon Jesus Christ like a DOVE. This means that the dove can represent the Holy Spirit.
Mark 1:10 "And straightway coming up out of the water, he saw the heavens opened, and the Spirit like a dove descending upon him" further laid more emphasis on the subject matter. Now, Dove is associated with holiness, divinity, and celestial being.
Dove is also associated with purity, because of its tender and calm nature. These are the reasons why the dove is associated with Holiness, divinity, and celestial being and when seen in dreams it's associated with PEACE.