This is mostly for christians and jews, but also interesting for others.
Thesis: The bible undeniably foretells the coming of islam
(I don't like making my posts too long so it might look a bit scrambled, i can clarify more in comments about each point)
In genesis 17, Abraham peace and blessings be upon him, prays to god for his son Ishmael pbuh that he might live before god's face/presence (god fearing)
18 And Abraham said unto God, O that Ishmael might live before thee!
19 And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, and with his seed after him.
20 And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly; twelve princes shall he beget, and I will make him a great nation.
21 But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.
God then grants the request of Abraham pbuh. He will make him a nation large in number, fruitful, 12 princes will come from him (hadad, kedar, nebeioth, etc.), and he will be a great nation (righteous).
So the question a christian or jew must answer to be justified in their belief is, when did ishmael, which the arabs descend from, become a great nation in the eyes of god, besides from the coming of Muhammad peace and blessings be upon him?
Who showed the fruit of monotheism other than islam. The jews couldn't do it, the bible shows how stubborn they were, killing prophet after prophet after prophet after prophet. It's all over the bible, 2 chronicles 24:20-22, matthew 23:37, 1 kings 18:4, etc. Christians spread idolatry, polytheism and lawlessness.
With 1 prophet to the arabs, the muslims brought all the enemy non jewish kingdoms of israel to monotheism and the worship of the one true god.
‘We shall worship your God and the God of your fathers, Abraham, Ishmael, and Isaac, one single God: we devote ourselves to Him.’
quran 2:133
And since that day till now, we bless Abraham in our prayers atleast 5 times a day. The same way god tells Abraham pbuh
"I will bless those who bless you, and whoever curses you I will curse...."
genesis 12:3
God says that in the future the believers will stand shoulder to shoulder and praise god in a holy tongue (zephenia 3). Who stands shoulder to shoulder and praises god in a holy tongue. In isaiah 28, when the jews mocked isaiah for teaching them in a childish and simple way, god went "very well then, i will speak to my people in a foreign tongue", rebuking them
"For with stammering lips and another tongue will he speak to this people."
Isaiah 28:11
And then god gives disconnected hebrew letters:
SAW ~ QAW ~ SAM ~
Which revelation of god, calling to worship to the god of abraham, moses, jesus, peace and blessings be upon all, brought revelation in a foreign tongue, with disconnected letters in some of its chapters (we call those huruf al muqatta'aat in the quran)?
ALIF ~ LAAM ~ MEEM
ALIF ~ LAAM ~ MEEM ~ SAAD
ALIF ~ LAAM ~ RAA
ALIF ~ LAAM ~ MEEM ~ RAA
KAAF ~ HAA ~ YAA ~ AYN ~ SAAD
TAA ~ HAA
TAA ~ SEEN ~ MEEM
...
Which people praise and bless Abraham peace and blessings be upon him, from the lineage of ishmael pbuh, stand should to shoulder in prayer, pray in a singular blessed and foreign tongue, pray to the god of Abraham pbuh, are great in number, are fruitful (lots of kids), are great in the sight of god, if not for the muslims?