When Muslims think or talk about the prophet of Islam, they accept apriori that his prophet-hood was true and absolute. The system of 'prophet-hood' had been in the culture of Middle-East Asia in earlier days. If we look at the history of the area, it becomes clear that barring aside the accepted list of prophets starting from Adam (mythical to me), there had been a long list of claimants of prophet-hood who were not accepted as prophets by the large main stream population of the time and place. Even during the time of prophet of Islam, there were at least five other prophet-hood claimants. Judaism and Christianity also had their share of such claimants. Among all such claimants, only a few (including Mohammad) succeeded while the rest of vast majority failed. This success or failure had nothing to do with truth or falsity of prophet. It was something like modern day election campaign. Ultimately one would win in one time and place. The false and, at times, impossible promises made by today's politicians to be-fool people and win election were similarly used by the prospective prophets of old time to get public recognition and acceptance of his prophet-hood. Islamic 'paradise' is one such false promise. It was ultimately the survival of the fittest (not the best) prophet claimant. There was nothing divine about it.
In Islam, utmost emphasis has been given on absence of other Allahs but Allah. The religion seems to be obsessively pre-occupied with denying the presence of other Allahs. The denial of the existence of other Allahs and formlessness of THE Allah (as against idol), could make Islam look different and new before the polytheists idolaters of 7th century Arabia. It was a marketing strategy. The Allah's attributes include worldly aspects, viz: punisher of disobedient and benefit-giver to sycophants. At times, Allah resembles more as a dictator than creator and caretaker of humans though humans constitute an infinitely minute proportion of the universe. Why Islam (or for that matter any religion) is absolutely concerned with this infinitely minute proportion of universe, i.e human beings?
Mohammad had to spend four decades of his life before putting his claim to be a prophet. It is unthinkable that Allah had wasted forty years before bestowing prophet-hood on Mohammad. Why Allah could not take the easiest way of telling the polytheists idolaters of Mecca about the prophet-hood of Mohammad much earlier? Abrahamic religions (Judaism, Christianity & Islam) give a convenient 'thumb rule' that God speaks to mankind only through prophets. But the actual reason is very simple. Because of HIS nonexistence, Allah could not communicate with the people. HE was simply projected by a person who claimed to be HIS messenger (prophet). In actual, the Allah was the imaginary double for the prophet. Prophet thus became inseparable from Allah and propagated his (prophet's) own ideologies in the name of Allah.
That convenient situation helped the prophet of Islam from taking any responsibility of all his misdeeds which were passed on as the wishes of Allah. In the process, the Allah got manipulated by the Mohammad to fulfill the latter's worldly objectives. The endeavor was boosted by the bla bla (religious carrot and stick) of life after death in grave, paradise, hell and Day of Judgment etc.. Muslims remain engaged with blasphemy, Kufr, Sirq, Haram and Najaiz etc.. Hujurs had programmed them like that in the childhood. Tablighi movement has reinforced the observance of meaningless Islamic rituals. Qur'an and Hadith are used as tools by the power hungry Ulema. They constantly issue Fatwas to keep the believers (educated or uneducated) perpetually indoctrinated.
Allah only exists in the heads of followers not alone, but in conjunction with the prophet (who was a human being). How can one believe in an Allah who needed a human prophet to establish HIMSELF? How can one believe in an Allah who needs to be constantly praised by the followers to thrive? How can one believe in an Allah who has failed to convert all humans of the earth to Islam even in 1400 years (much to the shame of prophet and ideologues)? These are the reasons as to why the apostates from Islam are violently condemned by Muslims to save prophet (& his Allah). However, at the end Allah remains as bogus as idol of idolaters and prophet as crook as a politician of Indian sub-continent. Muslims cannot exist without a fictitious Allah and HIS manipulative prophet. So the issue of prophet and Allah in Islam is existential in nature and essence. There is nothing spiritual or supernatural about prophet and his Allah.