Peter Ruckman (1921-2016 AD) wrote a series of "Why I Am Not" booklets, on a variety of religions and denominations. This is the Islamic installment in the series.
Ruckman's style of writing is best described as "rant" or "stream of consciousness". This makes for "interesting" reading.
Click to Expand Table of Contents
In the Introduction, Ruckman begins with an overview of why he isn't a Muslim. He introduces three reasons, the first two being that there is no prophecy in the Quran, and that Muslims, like Muhammad himself, had no assurance of Salvation. The third reason is quite "Ruckmanesque" - the fact that he hadn't heard its followers sing about Muhammad:
Why I Am Not a Moslem - Introduction, pg. XI-XII
That isn't all. The third thing is there are no songs about the founder. There is something ghastly wrong with a religion, where the founder claims to have gotten all his revelations from the Almighty God and talks about "no compulsion in religion," that produces over one billion followers who can't sing any songs about him. My, what a mammoth miracle: none of its believers can sing ten songs about the dead sinner who produced it....
No Moslem could find anything about the founder of their religion about which to sing to put in a song book containing even ten songs. And if he did, women wouldn't enjoy singing them. Of course, the obvious reason is the founder of his religion never got out of the grave, so when he died, there was no need to sing about him; he didn't come up. Evidently, it was joy and assurance that died with their founder. So it is his religion that is enforced by sword point, not by praising the founder in songs.
Chapter 1 - The False Cover-up For Islam's "Prophet", covers, broadly, the character of Muhammad. It begins with remarks on Surah 4:80 - "Whoever obeys the Messenger, he indeed obeys Allah. And whoever turns away, We have not sent thee as a keeper over them". Ruckman argues that because of such passages, Islam is better called "Mohammadanism":
Why I Am Not a Moslem - Chapter 1, pg. 3
This means that there is no such thing as Islam at all. It is Mohammedanism, but you put Islam there to cover up the fact that the whole religion came from an epileptic, sex-crazy, illiterate, fornicating killer who enjoyed killing people who didn't accept His religion.
Ruckman also picks up on a meaningful critique in this chapter - the ignorance of Muhammad as to the name of God, though he doesn't do a great job of explaining the true significance of the problem that this creates for Islam:
Why I Am Not a Moslem - Chapter 1, pg. 6
Mohammed didn't know God's name, so he called him "the god." Having made him "the god," Mohammed took the attributes ascribed to Jehovah in the Old Testament and applied them to "the god" without giving you "the god's" name. Allah never gave his name to anybody. He didn't give it to Mohammed or the angel who dictated the Koran to Mohammed.
This chapter skips around topics like crazy. Ruckman seemed to believe that Islam teaches that Jesus "either was raptured with Mary or died of old age at Kashmir, India" (pg. 9). The latter belief was a doctrine of the founder of the Ahmadiyya sect, Mirza Ghulam Ahmad (1835-1908 AD), so it appears Ruckman encountered some Ahmadiyya material at some point. Ruckman argues that Muhammad shunned the teachings of the New Testament, particularly. He also touches on Muhammad's dearth of prophetic ability, in comparison to the Biblical prophets:
Why I Am Not a Moslem - Chapter 1, pg. 7-8
If you want a real prophet, pick up Moses (Deut. 28-33); he is not even listed among the prophets. The Jewish Scripture is divided off into the Torah, the Nabhim, and the Kethubim. It puts Moses in a section in the Law, not the Prophets.
There are more historical prophecies given in one chapter in Genesis (Gen. 49) than there are in 114 chapters in the Koran. There are more historical prophecies in one chapter of Deuteronomy (Deut. 32) than there are in 114 chapters of the Koran. There are more prophecies in Genesis 3 and 9 (two chapters) than there are in 114 chapters in the Koran.
Chapter 2 - The False Cover-up For Islam's Bible, is a general critique of Islam. He begins speaking at length about how the Quran was allegedly delivered by Gabriel, who was supposedly a "600-winged angel" (Sahih al-Bukhari 3232, etc.). Ruckman, who believed "No angel who ever lived had wings" (pg. 15), takes objection to this detail. He notes the fact that the Quran denies Allah having a Son (Surah 2:116, 10:68, etc.), despite the Bible repeatedly testifying to the contrary (Genesis 6:4, John 1:12, etc.).
He then returns to his idea, touched on in Chapter 1, that Muhammad borrowed from the Old Testament, while shunning the New Testament:
Why I Am Not a Moslem - Chapter 2, pg. 19
Do you know where Mohammed got the idea of praying more than one time a day? He got it from David (Psalm 55:17) and Daniel (Daniel 6:10). Do you know where he got the idea of facing a city when you prayed? He got it from Daniel (Daniel 6:10) and Solomon (1 Kings 8:30). Do you know where he got himself set up as an armed religious leader leading troops? He got it from Joshua 19. Do you know where he got the idea of genocide for whole nations of unbelievers? He got it from Moses (Deuteronomy 20:10-18) and Joshua (Joshua 11:11-23).
Mohammed never had a single original idea in his head from the time he was born till the time he died: not one. You could write all he knew about new revelations on the back of a postage stamp.
I don't find this particularly compelling, though he goes on to list 2 more paragraphs of similar "parallels". The fact that Islam incidentally resembles some things from the Old Testament is simply a product of the Old Testament being long, and the types of parallels noted by Ruckman here aren't that remarkable. Those who have studied Islam deeply understand that Muhammad knew almost nothing about either the Old or New Testament, and therefore, definitely wasn't selectively stealing material from the Old Testament.
Ruckman then returns to Surah 4:80 ("Whoever obeys the Messenger, he indeed obeys Allah"), and points out some odd things in the Hadith, including that Satan lives in your nose at night, that having dogs as pets is wrong, that praying with eyes raised to Heaven is wrong, that Muhammad recommended drinking camel urine, and that Adam was 90 feet tall. He then resumes a sustained attack on the "winged angels" concept in Islam:
Why I Am Not a Moslem - Chapter 2, pg. 23
No angel has wings of any kind - literal or figurative. The beings who have wings are called cherubim and seraphim (Isaiah 6:2; Ezekiel 10:5). Therefore, "the God" (Allah) of Abraham certainly wasn't "the god" (Allah) of Mohammed, because Abraham "entertained angels unawares" (Hebrews 13:1) and gave them a meal (Genesis 18:1-16, 19:1), and so did Lot (Genesis 19:1-3, 19:10-13). Do you think they were women flapping their wings around?
Every angel in that Bible is a young man. Read Judges 13. Whoever gave Mohammed his material misled him completely and led him into a desperate, vicious lie which is denied in 66 books that were written before his great, great grandmother was born. If poor old Mohammed ever had an original idea, it died of loneliness.
Chapter 3 - The False Attitude Of "Islam" Toward Anti-Mohammedans, covers what Ruckman perceives to be an extreme double-standard in the way Muslims treat non-Muslims. He begins by talking about the fruit of Islam, and false religions more generally:
Why I Am Not a Moslem - Chapter 3, pg. 26
What this means is that when we talk about the "fruits of religion," we should never compare Bible Christianity with the fruits of any "religion." In Biblical Christianity, you don't have to do anything to get to Heaven; in all other religions, you do. You must work at it. Hence, you are subject to gross error and every form of iniquity known to man. Religions create wars (James 4:1-2). Biblical Christianity says you don't do anything to get eternal life; you accept what somebody else did. That is the difference.
So when we talk about the differences between Christianity and Mohammedanism, we have to make a distinction between State Christianity and Biblical Christianity. "Biblical Christianity" is something entirely different from Mohammedanism. On the other hand, Roman Catholic Christianity is just like Mohammedanism. They are both worldwide, international State religions that teach you get to Heaven by works, so they clash, and they both bring forth rotten fruit.
He then speaks on the fact that Muslims often perpetrate violence against disbelievers, as well as each other, and that this is the rotten fruit of a false religious system. Ruckman then touches on the fact that Islam denies Christ's Deity (John 20:28), His sonship (Matthew 3:17, 11:27, 17:5), His substitutionary death (Matthew 27:38), and His exaltation to reign forever (Luke 1:32-33), and that all such things are blasphemous claims to them, which Ruckman says spurs them to violence.
Ruckman, in this final chapter, summarizes his position as follows:
Why I Am Not a Moslem - Chapter 3, pg. 35
Mohammedans believe in praying, killing, and fornicating, and that is just about all they really believe. The conservative ones come over here to get an education to pass off as "Americans." They know how to take advantage of suckers.
I am not a Mohammedan because Mohammed never had any assurance of salvation all his life, and neither did any of his followers; nor do they have it now. I am not a Moslem because nobody sings songs about their own founder named Mohammed, and they don't like to be connected with his name. They prefer to be called "Moslems" (or "Muslims" as they like to spell it). I am not a Mohammedan because Mohammed, as a prophet, was just too pitiful for words; he couldn't prophesy any historical prophecies. I've got a Book where more than a hundred historical prophecies were fulfilled in the past, and more than 400 are coming up in the future.
The invective in Ruckman's writing is extreme to the point that it is distracting. Even with only the excerpts included in this review, one can get a pretty good sense of what they are in for. I find this distracting despite being on Ruckman's "side", but there are probably very few Muslims on earth who would ever be persuaded by a booklet like this, because they will be put off from being insulted in dozens of different ways throughout, and probably not even finish it.
Ruckman makes a few good points in this book, which I've attempted to highlight above. However, the book is quite disorganized, and the critiques aren't developed in enough detail. This is firmly in the category of a pre-internet, somewhat naïve critique of Islam.