One of the most used arguments by Islamists, is:
If the prophet allegedly created Allah (like what non-Muslims claim), why did then he spend nights praying and seeking forgiveness from the very deity he supposedly created?
Response:
A proof should be open and clear. For example, both the Meccan pagans and the Jews constantly asked Muhammad to show any miracle as proof of his prophethood. But both Muhammad and Allah were unable to show any miracle, and then Quran had to present several excuses for this inability to show any miracle. Please read our article: The Quranic Excuses for Muhammad's Inability to perform any Miracle
Thus, Muhammad's worshipping Allah cannot be used as proof of Muhammad's prophethood, as there could be many hidden reasons for this.
For example, one possible reason could be, Muhammad's primary weapon to make people believe in his prophethood was making them FEARFUL of Allah. And once they believe in him, then he also has to “maintain” this status to get worldly benefits. And in order to maintain it, he has to show that he was himself fearful of Allah, and he was worshipping him.
Another possible reason could be that Muhammad believed in stories of the Bible and divine punishments.
Muhammad knowingly pretended to be a prophet to gain personal advantages, but deep down he believed in the existence of a higher power who created him. He feared this divine being for deceiving people in his name.
This fear became evident when natural phenomena like solar eclipses or earthquakes occurred. During such events, Muhammad grew extremely anxious, worried that the real God might begin to punish him for fabricating a false god and falsely claiming prophethood. As a result, he would drop everything and devote himself to worship.
Similarly, in the Islamic story of Pharaoh, even though Pharaoh claimed to be a god, he also feared Allah, realizing that he was not a true deity. So when Moses warned him about impending divine punishment, Pharaoh would prostrate and beg for forgiveness from Moses' God. And due to this act of asking forgiveness by Pharaoh, Allah postponed the punishment many times.
This story of Pharaoh and many plagues in Egypt was first appeared in the Bible (Exodus). But every time Pharaoh asked for forgiveness, and the divine punishment of different plagues disappeared due to asking for forgiveness.
Muhammad copied this story of plagues from the Bible in the Quran 7:134-135.
Thus, knowing himself that he was only deceiving people in the name of real God, Muhammad became extremely fearful whenever any natural disaster occurred (while according to other stories of the Bible, natural disasters were the way that God punished people for their sins).
The sun eclipsed during the time of the Messenger of Allah (ﷺ). He stood in great anxiety fearing that it might be the Doomsday, till he came to the mosque. He stood up to pray with prolonged qiyam, ruku', and prostration which I never saw him doing in prayer; and then he said: These are the signs which Allah sends, not on account of the death of anyone or life of any one, but Allah sends them to frighten thereby His servants. So when you see any such thing, hasten to remember Him, supplicate Him and beg pardon from Him
Whenever a strong wind blew, anxiety appeared on the face of the Prophet (fearing that wind might be a sign of Allah's wrath).
'A'isha, the wife of the Messenger of Allah (ﷺ), reported: I never saw Allah's Messenger (ﷺ) laugh to such an extent that I could see his uvula-whereas he used to smile only-and when he saw dark clouds or wind, (the signs of fear) were depicted on his face. I said: Messenger of Allah, I find people being happy when they ace the dark cloud in the hope that it would bring rain, but I find that when you see that (the cloud) there is an anxiety on your face. He said: 'A'isha, I am afraid that there may be a calamity in it, for a people was afflicted with wind
Hassan Radwan