Yes, Jesus is our Brother and Savior (Hebrews 2:11-15)
But Jesus had 4 blood brothers as well since Mary was the actual mother of 5 boys.
They would not have been Mary's children, since Jesus was concerned to put her into the care of His beloved disciple John after His death, unnecessary and unthinkable if she had grown children to look after her.
No one thought such a carnal-minded thing --- Mary bearing more children --- until 1500 years after Mary's passing from this life.
The early Christians would have died to defend Mary's perpetual virginity. You can see it written on the catacomb walls of the underground cemeteries under the city of Rome. Thus attested the martyrs: "Beatae Mariae Semper Virgine."
`
`
`
Jesus has many millions of brothers; and as you know, of course, this does not mean we were all born from Mary's womb. Nobody was born from Mary's womb but Jesus.
Interestingly, though, it is true in a spiritual sense: we are all children of Mary.
Revelation 12:17
"The serpent became angry with the woman. So it went away to fight with her other children, the ones who keep God’s commands and hold on to the testimony of Jesus."
It’s a Catholic thing. I fear the dogma will lead to re-adoption of pagan forms of worship, which syncretism crammed together with Constantine’s Christianity.
http://www.albatrus.org/english/religions/pagan/pagan_origin_mary_worship.htm
The Bible refers to people as "brothers and sisters" of Jesus, but never refers to any of them, except Jesus himself, as children of Mary.
James the lesser is identified as a "brother of the Lord," but his parentage is specified also: he is the "son of Alphaeus" (Mt 10:3, Mk 3:18, Lk 6:15). Jude Thaddeus is also called a "brother of the Lord," but Acts 1:13 says he was actually James' son. Pretty clearly, the Scriptures are using the word "brother" a lot more generically than we would.