Setting aside the moslem issue for the moment the sweep and conquest of Islam in its first century of existence is truly astonishing. How does one go from nothing, create a new "religion," enlist so many converts, and go on the warpath against the biggest, strongest and best equipped armies in the world and WIN everywhere all in less than one hundred years? That is incredible. How did they manage to do that? Just amassing the required wealth to undertake that is amazing.
Consider this line from the article: “While many religions rejected the doctrine of Jesus as Messiah or the concept of the Trinity, Islam was the only major world religion born with Christianity already in full bloom that consciously defined itself in direct opposition to the core Christian doctrines of the incarnation, atoning crucifixion, and resurrection.”
Islam is expressly of the spirit of antichrist and has been since its founding.
So now look at Matthew 4:8-9 “Again, the devil taketh him up into an exceeding high mountain, and sheweth him all the kingdoms of the world, and the glory of them; And saith unto him, All these things will I give thee, if thou wilt fall down and worship me.”
There are many things that could be said of this passage but in this context it is this that seems relevant: Islam’s spread was among and by those who worshipped the beast.
The contrast between the Kingdom (Christ told Pilate that His Kingdom was not of this world for if it was then His disciples would be fighting) and the bloodbath of early Islam cannot be starker.
And the reason should be clear: the devil’s kingdom is only in this world and it ends badly for him. So his disciples fought, and fought hard, once they’d been given a doctrine suitable for that purpose.
There is said to be a story about a man, IIRC, who had a merchant (on whom much of his own income depended) murdered because the merchant had slighted Islam or the prophet ... when he did this and it became known a third man was so impressed that he would murder for his faith that he became Muslim.
At the time of Islam’s foisting itself on the world there had been centuries worth of the rejection of the Gospel and so many people for it to harvest and direct towards its ends.
Even so, the Byzantine Empire could have thwarted the expansion of Islam if it had recognized the threat it posed.
But you're correct, the military conquests of the early Caliphate were remarkable. Robert Spencer details much of this in his book, The History of Jihad, from Muhammed to ISIS.
The conquest of Islam in the 6 to 14 centuries the simple, if you inspire people to frenzied violence , And engage their last for both gold and sex slavesthey will always win until the great equalizer is invented
the firearm
Christ the Savior said the meek shall inherit the earth
This is of course True in the long run it is much as those that have found inner peace have conquered over their sins in this life
Those human beings then can set forth to help other human beings in this endeavor
Islam and many other forms of philosophy of this life stress selfishness and greed which are a sure form of self destruction and a path to hell not only on this earth but in the afterlife