What one could say is that the proper place of Islam in salvation history is as the religion that is completely anti-Trinitarian and anti-Christological while yet retaining the shell of the Gospel. When you follow these implications, it works out all the deficiencies of the religion.
Islam and all other major spiritual disruptions in the last 1700 years are NOT just crazy and random... They are following a logical, theological path. I think spoke of this before in other essays. They start from the top of the Catholic Pyramid of Truth, as it were, and work down, from the greatest sources of truth, down to the least. Hence, from God as Triune and Incarnate [Heresies 300-600~, Islam], to Peter, Supreme Apostolic Successor [Great Schism, 1000~], to General Bishops and Tradition [Protestantism, 1500~], to Scripture [Enlightenment, solo-Ratio Ages, 1500 - 1700~], to Reason [Secular Apostasy, 20th Century to Present].
For now, we can focus on the earlier phases of this theological structure. From this view, Islam is not just coming up out of nowhere. It is is the logical conclusion of the first three hundred years of heresies. More specifically, we can in fact say that the first age of heresies that are post-pagan Rome consists in PARTIAL attacks on the Trinity and Incarnation, ~ AD 300 - 600: Arianism, Monophysitism, Monothelyte, Nestorianism. More specifically, almost as bad as Islam, Arianism completely denied the Trinity and Incarnation, reducing Christ to a mere creature. The remainder of most heresies that assaulted the Church from then until the rise of Islam were effectively assaulting some aspect or aspects of the Mysterious Nature of Christ as the Divine God-Man, as fully human and fully divine, One Person, two Natures, the Eternal Son, uncreated, the body and soul of Christ, created, the two wills of Christ, in perfect accord, the limited knowledge of Christ in His human nature, etc.
The second age is then COMPLETE attack on the Trinity and Incarnation: Islam. Basically, what Islam seems to do in almost all cases is: take Judeo-Christianity and do what Christianity has UNLESS....UNLESS the element of Christianity involves a REDEMPTION of an Old Testament type.
Like Christianity, it seeks the world to become united in a spiritual kingdom of truth and good. It is monotheist but rejects the Trinity, so its God is Monotarian. It rejects the Incarnation, so Christ is merely a messenger and not God. And finally, unlike Arianism, Islam attacks Jesus in full by saying there is a revelation that goes BEYOND Him. "We await no new Revelation, for God has spoken His Final Word in Christ." CCC. So, Islam goes the ultimate step beyond Arianism: Arianism indeed totally denied the Trinity and Incarnation, but they didn't suggest that God had more to say BEYOND Christ. Islam DOES. This makes their attack on the Nature of God in mystery complete.
Now to elements that were redeemed.
The blood curdling take over of the holy land sanctioned by God to the Jews in the OT was necessary to give a picture of casting out all evil in a culture. The Church redeems this. We don't go in and slaughter the people. We "cast out" what is SPIRITUALLY unclean. In FACT, maybe not CAST OUT, but RENEW... or TRANSFORM. Islam rejects this fulfillment, and so tends to take lands by force, like Israel did.
Too, the Church fulfills Pentecost: the tongues in multiplication were initially a curse: they divided man and set him up for bloodshed and division, at Babel. Pentecost did not redeem language by restoring UNICITY, but retaining the BEAUTY by DIVERSITY, so that all, though diverse, can UNDERSTAND one another. Indeed, multiplicity and diversity in nations and cultures is a BLESSING from God, like a field of many different flowers.
Like the little flower, St Therese of Liseux, one of many female Doctors of the Catholic Church, said: one can object, that we are not all the same, we have different chances of being saved. But, if all were roses, where would be the lily?
The devil knows theology, and so he can set up a perfect religion that has theological precision. And God lets him, because He can use it, use it to show the deficiencies, so that when the deficiencies reach apocalyptic proportion, He is able to show humanity their need for what Islam lacks.
So, again, the Church REDEEMS the multilingual and the multicultural. When it converts a society it does NOT annihilate its language or culture. It TRANSFORMS them, ELEVATES them. Notice, ISLAM does NOT redeem those. ISLAM's solution to multi-language is ANNIHILATION of language, FORCING unicity. It FORCES Arabic. Note, all Islam speaks Arabic. ALL Islam has same culture. Same burka, turban, mosque.
What did JESUS do about the Old Testament DEATH PENALTY?! It is one of the most beloved, famous scenes in the Gospel. The woman caught in adultery. Jesus shewed the ultimate divine interpretation. God instituted hard core, many times capital, punishments for serous sin in the OT as a picture of HELL. The ultimate fate of serious sin to death is ETERNAL death. God needed to give an initial revelation of the gravity of serious sin, so He gave the best possible picture: PHYSICAL DEATH.
But JESUS is the one who REDEEMS that Old Law, by showing that God does not ultimately want to punish us in this life. He wants to have mercy and save us. Hence, the NT equivalent for serous sin is now confession, amendment of purpose, not death. Islam REJECTS this, since Jesus did it, since it is a NEW Testament redemption, like the elements we have discussed so far. So Islam goes BACK to the OT. Hence why Islam tends to have SEVERE, almost MERCILESS PUNISHMENTS for serious sin. Cut off hand of thief. Girl gets pregnant, stone her. Same sex? Just as they were stoned in OT, they are killed by Islam.
They also have dietary restrictions, like OT. NT renewed that. Pork was just a symbol of what is SPIRITUALLY unclean. They remain OLD.
The immediate implications of rejecting the Trinity and Incarnation: The Revelation of the Trinity and Incarnation opens up the full understanding of the mystery and sign of human sexuality. More specifically, the Eternal Procession of the fully equal in majesty Person of the Son from the Father reveals why woman emanates from man, coequal in priceless worth. Then, that the total, reckless exchange of love and truth between the Divine Persons of Father and Son is eternally the Holy Spirit images that the total, reckless exchange of love between man and wife can become a third person of equal immeasurable worth, a child. Hence, God is veritably a Family of Love, just as the human family images the most deep and wonderful love.
Too, the man/woman relationship in the physical and emotional sense is seen, in the Incarnate Word, as an image of the SPIRITUAL relationship between the Creator and the creature in the following sense: just as man comes downs upon the woman, overshadows her, and lovingly enters her inner being, ultimately climaxing by pouring forth within her the seed of life, to bring forth of child that has intellect and will, like the two as one flesh, so the Creator, God, comes down upon the human creature, overshadows them, and enters their inner soul, pouring forth by intimate procession, truth and grace into the soul’s inner being, truth for the intellect, and grace for the heart.
Also, of course, Christ reveals what no Jew sees coming: at the time of Christ’s first coming, the orthodox Jews know that there shall be a resurrection at the end of time, hence indicating the dead shall receive back their bodies. What is impossible to fathom, that they would never know unless God opened it up to them, is that their sexual nature, while not being abrogated, will nevertheless no longer be exercised in activity. “They shall be as the angels”, the Christ told the skeptical Sadduccees.
Once again, these New Testament realities are explicitly denied by Islam, and so God in Islam, not being a family of love, but merely one Person, simply is not as loving and beautiful as the Christian God. Hence why Islam has a God that is more about submission rather than a loving Father and Savior. Too, since the NT reveals the ultimate meaning of human sexuality, namely, as seen above, that we shall marry God in the end, and not any earthly spouse, and since, again, Islam rejects any NT redemption, Islam regresses to sex in the Resurrection, which we all know the dragon has twisted into diabolical deception in modern times, with aberrational terrorist theology suggesting that if one dies in suicide martyrdom, one will be be rewarded with many virgins in heaven.
Also, if we look closer at the Christ, we see three great components:
Christ shows us that God loved us so much from the foundation of the world, that He desired to SUFFER for us in both SOLIDARITY and to FORGIVE us, to pay the debt we cannot pay. Christ’s solution, therefore, to suffering is to call us to unite our sufferings to God and offer them as mercy and plea for the redemption of our enemies.
This aspect is simply largely absent from Islam. Islam is just not as merciful (refer back to the harsh penalties). Forgiveness of enemies is just not as ingrained into Islam as it is in the Gospel.
This sums up most of the problems of Islam. It also shows that Islam does not make a random appearance in salvation history. It is logical. It brings the first heresies against God’s Mysterious nature to their logical fullness.