“what makes it Halal?”
It is halal if the animal is sacrificed to the pagan idol of the black rock in Mecca.
This ritual is obviously meaningless, as allah is a nothing (or a demon) and the rock is a rock.
Nonetheless, as a Christian, I fall back on the teaching in Acts to avoid eating meat sacrificed to idols, to avoid giving credibility to the evil religion, so as not to lead weaker Christians astray.
I was born and raised in the Middle East specifically Lebanon. Where I went to a Christian school and used to recite the prayers and listen to our teachers reading from the Bible. I also have had a lot of Christian friends and neighbors whom I spent a lot of time with, had dinners and lunches with, had a lot of open discussions about religion, celebrated Christmas and Easter with.
Let me tell you something Allah and Ilah are Arabic words of God. And that is the word that Ive heard from all the Christians that I knew my whole life and read in the Arabic bible with my own eyes. On top of that, in the Aramaic language which was the language that Jesus spoke, the word Alaha means God. In the Hebrew language its Elohim and Eloah. So as you notice Allah, Ilah, Alaha, Elohim, and Eloah, they all mean God.
Please check this site http://www.learnassyrian.com/aramaic/church/church.html
As to halal slaughtering, the word halal means permissible. And halal slaughtering consists of using a well-sharpened knife to make a swift, deep incision that cuts the front of the throat, the carotid artery, windpipe, and jugular veins to cause the least amount of suffering to the animal. Allah’s name must be pronounced during slaughter (bismillah Allahou Akbar) which means in the name of God and God is the greatest.
In the Middle East Muslims eat from Christian butchers and Christians eat from Muslim butchers because over there halal (permissible) is the only way of killing the animals. It has nothing to do with sacrificing the animal to Allah.
Sacrificing to God is a whole different thing which we do when celebrating the sacrifice holiday which commemorates the story about the prophet Abraham when he was asked to sacrifice his son. The story that is written in the Bible as well as in the Quran.
One last thing, believe it or not Muslims believe in Jesus and the Virgin Mary. There is a whole chapter in the Quran under the title of sourat Maryam (Maryam is the Aramaic and Arabic word of Mary) and it tells the story of sitna Maryam (our lady Maryam) thats how Muslims call her how she got pregnant without being touched by a man and how she was mistreated by people How she gave birth in Jerusalem, how Yeshua or Issa alayh el salam (Jesus peace on him) talked to people when he was an infant and all the miracles he did... We even name our kids Maryam and Issa up till nowadays. We also believe that Jesus will come back to live 40 years on earth before the Day of Judgment.
Well of course there are some differences in some believes between the Christians and Muslims but this is not our subject here.
N.B It is well known that Christianity is the religion of love and forgiveness. Thats what was Jesus known for. People need to open their hearts and minds, accept others, and respect them.