As a Christian, when speaking to Muslims, their arguments against us typically lead to the deity of Christ, the reverence we give Him, the concept of the Trinity, or similar things. Muslims are very strict, at least verbally, on their idea of tawhid–the idea that Allah is one. When put into practice and compared to Christianity however, one can quickly see that Muslims, whether intentionally or not, may give the same or very close and similar authority and worship, to Muhammad as Christians do to Jesus.
For example, under Islamic practice, not only are some Muslims likely not understanding and even breaking their idea of tawhid, which is one of the most fundamental, important concepts in Islam, but they are also committing shirk. If you are unaware of shirk, it is the sin of idolatry or worship of anything aside from God. According to Wikipedia, it literally means “ascribing or the establishment of ‘partners’ placed beside God.” When we look at the Quran and the hadiths, however, the idea of Muhammad being “partners” with Allah is exactly what we see.
Qadi Iyad ibn Musa (1083–1149), an imam who later became qadi, wrote a very well-known and circulated book known as Ash-Shifa–“The Healing.” In a Wikipedia article citing `A’isha Bint `Abdurrahman Bewley, “this work was so highly admired throughout the Muslim world that it soon acquired a sanctity of its own for it is said: “If Ash-Shifa is found in a house, this house will not suffer any harm…when a sick person reads it or it is recited to him, Allah will restore his health.” Apparently, it is a very influential and important work among Muslims. Within the pages of this text, however, we find this:
The fact that mention of the Prophet is directly connected to mention of Allah also shows that obedience to the Prophet is connected to obedience to Allah and his name to Allah’s name. Allah says, “Obey Allah and His Messenger” (2:32) and “Believe in Allah and His Messenger.” (4:136) Allah joins them together using the conjunction xva which is the conjunction of partnership. It is not permitted to use this conjunction in connection with Allah in the case of anyone except the Prophet.
According to Qadi Iyad, using the conjunction “and” when speaking of Allah and anyone else is strictly prohibited as it equates to a partnership. There is, however, an exception to the prophet Muhammad. In other words, Qadi Iyad is allowing a partnership between Allah and Muhammad, which breaks the idea of tawhid and at the same time is shirk.
There are other hadiths mentioned in Ash-Shifa, including quotes from Muhammad, that completely condemn the use of “and” between Allah and another being:
Hudhayfa said that the Prophet said, “None of you should say, ‘What Allah wills and (wa) so-and-so wills.’ Rather say, ‘What Allah wills.’ Then stop and say, ‘So-and-so wills.’“
Al-Khattabi said, “The Prophet has guided you to correct behaviour in putting the will of Allah before the will of others. He chose ‘then’ ( thumma ) which implies sequence and deference as opposed to ‘and’ (wa) which implies partnership.”
Something similar is mentioned in another hadith. Someone was speaking in the presence of the Prophet, may Allah bless him and grant him peace, and said, “Whoever obeys Allah and His Messenger has been rightly guided, and whoever rebels against them both (joining them together by using the dual form)…” The Prophet said to him, “What a bad speaker you are! Get up! [Or he said: Get out!]”
As you can see, it is strictly forbidden, even according to Muhammad, to use the conjunction “and” when speaking of Allah and another. It implies an equal partnership among the two parties mentioned, and if Allah is one of the parties, then it is putting the other party as partner to Allah.
If we look to the Quran, we can find that the use of “and” when speaking of Allah and Muhammad is quite frequent:
And obey Allah and the Messenger that you may obtain mercy. (Surah 3:132)
These are the limits [set by] Allah, and whoever obeys Allah and His Messenger will be admitted by Him to gardens [in Paradise] under which rivers flow, abiding eternally therein; and that is the great attainment. And whoever disobeys Allah and His Messenger and transgresses His limits – He will put him into the Fire to abide eternally therein, and he will have a humiliating punishment. (Surah 4:13-14)
And whoever obeys Allah and the Messenger – those will be with the ones upon whom Allah has bestowed favor of the prophets, the steadfast affirmers of truth, the martyrs and the righteous. And excellent are those as companions. (Surah 4:69)
The only statement of the [true] believers when they are called to Allah and His Messenger to judge between them is that they say, “We hear and we obey.” And those are the successful. (Surah 24:51)
It is not for a believing man or a believing woman, when Allah and His Messenger have decided a matter, that they should [thereafter] have any choice about their affair. And whoever disobeys Allah and His Messenger has certainly strayed into clear error. (Surah 33:36)
The Quran constantly implies a direct partnership between Allah and Muhammad, by the use of the conjunction “and” when speaking of the two together. This is a major contradiction to some hadiths and the words of Muhammad. Notice the last verse in the list above, Allah is working with the Messenger to decide upon a matter. The two are working together, which directly claims some form of a partnership. Again, this technically breaks tawhid and commits shirk.
In Surah 4:65, we read again that Muhammad has been made to be the judge over Muslims whose belief does not count until they are in submission to Muhammad:
But no, by your Lord, they will not [truly] believe until they make you, [O Muhammad], judge concerning that over which they dispute among themselves and then find within themselves no discomfort from what you have judged and submit in [full, willing] submission.
Not only is this verse contradictory to other Muslim sources which state that Allah does not have a partner, but it is contradictory to the word Islam itself. According to Muslims the word Islam means Submission to Allah:
If anyone desires a religion other than Islam (submission to Allah), never will it be accepted of him; and in the Hereafter He will be in the ranks of those who have lost (All spiritual good). (Surah 3:85)
Yet in verse 4:65 above submission to Muhammad is required for true believers.
Finally, for one to be a Muslim they must recite the shahada, which is the first of the Five Pillars of Islam. It is a confession of faith of sorts in which one must confess Allah and Muhammad in order to be a Muslim. The shahada reads:
La ilaha illa Allah wa-Muhammad rasul Allah.
There is no god but Allah and Muhammad is the prophet of Allah.
While Muslims frequently rebuke Christians for worshiping Jesus as the divine son of God, it is apparent that Islam in many ways calls for Muslims to do the exact same thing with Muhammad. The hadiths and other writings are even contradictory on the matter, but the Quran is very clear that Muhammad is, indeed in some way a partner to Allah. Muslims may call it respecting Muhammad since to them he was a messenger of Allah, given some authority ver them, is said to be the best example for them. Likewise to us, Christians also have been given to Christ in the sense that He will judge us and has authority over us. Despite Muslim misunderstanding Jesus is not God the father, but is begotten of and divine as God. As God’s son we should respect Him. And follow His teachings. This is something Christians and Muslims should find a understanding on. So Muslims who are seeking to attack our practices are not only being very hypocritical in their ideas of our relationship with Jesus Christ, but they also have basically taken the idea of Christianity and in some way applied it to Muhammad in Islam and simply fail to see it.
On a final note, this is not to disrespect Muslims, but to show that their ideas of criticism of our worship is sometimes hypocritical. In the end it is better to understand each other first rather than fuel hatred.
 https://en.wikipedia.org/wiki/Shirk_(Islam)  https://en.wikipedia.org/wiki/Ash-Shifa  Ash-Shifa, Part 1, Section 1, Chapter 1  Ibid