Acts 2:11 confirms Jews of Arabia were at Pentecost.
Perhaps the first Arab Christian was Agabus, the Prophet mentioned in Acts 11. Some have argued his name is neither Hebrew or Aramaic or Greek but makes most sense as being Arabic. Since I agree with Bill Cooper in After The Flood that the Idumeans were from Ishmael's son Dumah rather then Edom, and given the influence of the Nabatean Kingdom of Petra at this time, that certainly seems plausible.
Paul in Galatians says he traveled to Mt Sinai in Arabia. But that doesn't quite tell us anything about Arabs who were early Christians.
In the New Testament itself the Arabian presence in The Church is small. But in the coming centuries their influence will be quite important. But constantly overlooked because of the Greek and Roman biases in how Early Church history was recorded and is still studied.
The Petra based Kingdom wasn't the only Nabatean Kingdom. The people of Osroene were also Nabateans. The Nabateans came from Nebojath/Neboiath the Firstborn Son of Ishmael. Many historians doubt the traditions of Abgar V becoming a Christian, and on that they may be right. But there is little doubt that either Abgar VIII and/or Abgar IX was a Christian. And I'm inclined to believe the theory that Lucius of Britain of the Liber Pontificals was actually a scribal error for Lucius Abgarus of Birtha or Birecik.
Philip The Arabian was a Roman Emperor of the first half of the Third Century. He was born in Arabia. There is a controversial belief that I have become convinced of that he was actually the first Roman Emperor to be a Christian, even before Constantine.
Eusebius refers to both Abgar and Philip as Christians but neglects to mention that they were both Arabs.
I personally have a theory that Helena, the mother of Constantine, born about 250 AD, may have been a descendant of an Abgar of Edessa. But that may be for another post some day.
The Ghassamid and Lakhmid kingdoms both formed around the late 3rd and early 4th centuries, and both became Christian kingdoms pretty early on. The former mainly in modern Jordan, but included the Golan Heights and a little bit of Syria. The latter in part of modern Iraq west of the Euphrates river. They and the Tanukhids were among many Joktanite tribes of Yemen who had migrated north following the destruction of the Ma'arib Damn and the conquests of the Himyar Kingdom.
From the Tanukhids came Queen Mavia, who reigned from 375-425 AD. There is disagreement over whether she was raised a Christian or converted. She long before Muhammad had a dream of creating a united Arab Kingdom. But she was betrayed by Theodosius, the same Roman Emperor who first officially made Christianity the State Religion. Under her a Bishop named Moses was appointed the first Arab Bishop of the Arabs.
The Lakhmid Kingdom would exist until just before the birth of Islam as I'll discus below. The Ghassamid Kingdom lasted a little longer and was eventually conquered by the Muslims.
I want to mention the Encyclopedia of Pleasure which is a collection of Arabic stories involving Lesbianism that have been preserved. One of the stories is set before Islam, during the lifetime of Muhammad but before he had his first "vision" at age 40 in 610 AD. Because at least one of the two women in the story would have been a Christian.
One of the stories told in the book is a story about the first Arab lesbian Hind Bint al-Khuss al-Iyadiyyah, known as al-Zarqa’, and her love to a Christian woman Hind Bint al-Nu`man, who was the daughter of the last Lakhmid king of Hira in the 17th century. When Hind Bint al-Khuss al-Iyadiyyah died, her faithful lover "cropped her hair, wore black clothes, rejected worldly pleasures, vowed to God that she would lead an ascetic life until she passed away…" She even built a monastery to commemorate her love to al-Zarqa'
Sahar Amer (2 May 2009). "Medieval Arab Lesbians and Lesbian-Like Women' Journal of the History of SexualityThe Lakhmid king in question is al-Nu'man Ill ibn al-Mundhir. From what we know historically he did have a daughter who's name isn't mentioned.
Nevertheless, according to creditable historical accounts, when Khosrau II demanded Nu'man's Christian daughter as part of his extensive harem, he refused the Shah's demand. In response, Khosrau II had him crushed by elephants; however, according to a Syriac chronicle, Khosrau invited Nu'man to a feast where he was dishonored and trapped;
Philip De Souza and John France, War and peace in ancient and medieval history, p. 139; Khuzistan Chronicle 9Interesting that he was so determined not to marry his daughter off in a back then perfectly normal political marriage. And we have a completely different tradition that his daughter was a very Monogamous Lesbian. I suspect the story may well be historical.
Some historians have even speculated that a larger percentage of the family Muhammad came form then is usually assumed was either Christian or Jewish. As is his family is known to have included at least one Christian, who I mention at the start of this study.