Allah subhanhu wa teala sais: "Indeed in the Messenger of Allah (Muhammad ) you have a good example to follow for him who hopes in (the Meeting with) Allah and the Last Day and remembers Allah much." ( Surah Al Azhab, Ayah 21)
"So wait patiently (O Muhammad ) for the Decision of your Lord, for verily, you are under Our Eyes , and glorify the Praises of your Lord when you get up from sleep." ( Surah Al- Tur, Ayah 48)
"Nun.
[These letters (Nun, etc.) are one of the miracles of the Qur'an, and none but Allah (Alone) knows their meanings].
By the pen and what the (angels) write (in the Records of men).You (O Muhammad ) are not, by the Grace of your Lord, a madman.
And verily, for you (O Muhammad ) will be an endless reward.
And verily, you (O Muhammad ) are on an exalted standard of character.
You will see, and they will see,Which of you is afflicted with madness.
Verily, your Lord knows better, who (among men) has gone astray from His Path, and He knows better those who are guided.
So (O Muhammad ) obey not the deniers [(of Islamic Monotheism those who belie the Verses of Allah), the Oneness of Allah, and the Messenger of Allah (Muhammad ), etc.]" ( Surah Al Qalam, Ayah 1-8)
Dear brother in humanity, as you can read from these ayahs Allahs Deen is based on beliving in one and only One God( Allah), beliving in all Allahs Prophets( Issa a.s, Mussa a.s, Ibrahim a.s.) and beliving that Muhammed sallahu alayha wa saalam is the Last Messanger of Allah, beliving in His Angels, Qadr of Allah and Day of Judgment. This is Tawheed in Islam and these are basic priciples of Islam and if only one part of it is missing than one can not be a Muslim.
Brother if you belive in Quran and if you belive in only One God, than you must aslo belive in our Prophet Mohammed sallahu alayha wa saalam and that Quran was revealed to him because Allah subhanaha wa teala tell us in Quran that Mohammed sallahu alayha wa saalam is His Servant and Last Messanger of Allah and proof of his existence and of Islam is Quran its selfe Alhmadulillah.
All Prophets which were sent before were sent only to one group of people and they all called in belif in only One God ( Allah) without associenting Him a partner in anything, fullfilling obligation toward Allah ( salah, zakah, fast) and staying away what Allah has forbidden us. And this is Islam brother, belif in Only One God, His Last Prophet Mohammed sallahu alayha wa salam and belif in Quran and Sunnah ( way of life of our Prophet sallahu alayha wa salam) because Allah sent His Last Prophet to guide people from darkness to light,toward belif in Only one God and guiding them toward happy and pure life and way of life which Allah is pleased and way of life which will bring them only thier own good on this World and Ahirah Inshallah.
I also think it will be good Inshallah if you read book " The Sealed Nectar" by author Saifur Rahman al-Mubarakpuri which explain in detail life of our Prophet sallahu alahya wa salam.
May Allah guide you brother toward Islam. Ameen.:tti_sister: