Spiritus,
I will continue to make my case on the heresies of Vatican II and its docuмents.
The doctrine of Mohammed is merely a rather confused rehashing of several ancient heresies, Judaizer, Arian and maybe even Gnostic with regard to the Crucifixion.
Without a doubt, "Who is a liar but he that denies that Jesus is the Christ? He is AntiChrist, who denies the Father and the Son".
In the light of the need of proper and effective Catholic missionary outreaches to the Muslim world, I agree such a meaningless passage is of little use.
But I believe the point on which you make an equivocation is when you impliclitly assume that worship offered cannot be false worship. Muslims, like even Jews today who keep the law, call on the God of Abraham, but each of their worship is conducted and regulated not in Spirit and in truth, but is false and "in vain do they worship me, teaching for doctrines the commandments of men". Thus, the Baltimore Catechism says,
Q. 1148. How do we offer God false worship?
A. We offer God false worship by rejecting the religion He has instituted and following one pleasing to ourselves, with a form of worship He has never authorized, approved or sanctioned.
On a somewhat related note, forgive me for the length, St.John the Damascus (b.676 A.D), a declared Doctor of the Church, argued with the Mohammedans thus,
Moreover, they call us Hetaeriasts, or Associators, because, they say, we introduce an associate with God by declaring Christ to the Son of God and God. We say to them in rejoinder: ‘The Prophets and the Scriptures have delivered this to us, and you, as you persistently maintain, accept the Prophets. So, if we wrongly declare Christ to be the Son of God, it is they who taught this and handed it on to us.’ But some of them say that it is by misinterpretation that we have represented the Prophets as saying such things, while others say that the Hebrews hated us and deceived us by writing in the name of the Prophets so that we might be lost.
And again we say to them: ‘As long as you say that Christ is the Word of God and Spirit, why do you accuse us of being Hetaeriasts? For the word, and the spirit, is inseparable from that in which it naturally has existence. Therefore, if the Word of God is in God, then it is obvious that He is God. If, however, He is outside of God, then, according to you, God is without word and without spirit. Consequently, by avoiding the introduction of an associate with God you have mutilated Him. It would be far better for you to say that He has an associate than to mutilate Him, as if you were dealing with a stone or a piece of wood or some other inanimate object. Thus, you speak untruly when you call us Hetaeriasts; we retort by calling you Mutilators of God.’
It seems to me that one of the great Fathers of the Greek Church, while rejecting wholly this deplorable heresy, still did not hesitate to speak pure and simply in this way.