"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: and lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased." (Matthew 3:16-17)

"And straightway coming up out of the water, he saw the heavens opened, and the Spirit like a dove descending upon him: and there came a voice from heaven, saying, Thou art my beloved Son, in whom I am well pleased." (Mark 1:10-11)

Now when all the people were baptized, it came to pass, that Jesus also being baptized, and praying, the heaven was opened, and the Holy Ghost descended in a bodily shape like a dove upon him, and a voice came from heaven, which said, Thou art my beloved Son; in thee I am well pleased." (Luke 3:21-22)

Matthew says that the Holy Spirit was "descending like a dove, and lighting upon him" - This talks about the manner in which the Holy Spirit descended. Matthew says He flew down like a dove.

Mark says, "and the Spirit like a dove descending upon him" - This is very similar if not identical to Matthew.

Luke says, "and the Holy Ghost descended in a bodily shape like a dove upon him" - He is saying that the Holy Spirit was shaped like a dove but it does not expressly say that it was actually a dove.

So which is it?

To argue what "like a dove" means actually misses the point of this passage entirely. To find the importance of this included detail we need to look at what all three accounts have in common. What is remarkable in all three accounts is that the Holy Spirit (Ghost) is present and visible!

And not only that. The Son is present and visible. The Father is present and His voice is heard from heaven.

The point is the entire Trinity of the Godhead is present at one place and time!