Allah: Allah is the personal name of God Almighty. Open a Arabic Jewish/Christian Bible (see Genesis Chapter 1) and you will see Allah (الله) written everywhere instead of God Almighty. Allah is defined in Quran as someone who is Unique, someone who has power over all things, someone who does not depend upon anyone for anything, someone who has neither ascendants or descendants, no one is like Him and neither He nor His attributes can not be imagined, if you can imagine any aspect of Him, that is not Allah. Example, Allah says of His Mercy that He sent only 1 part on Earth and kept 99 parts with Him for the Day of Ressurection. This one part is responsible for mercy even animals show to each other. So, to imagine His Mercy you have to divided into all days life has survived and will survive on earth and then distribute that it to all animals and humans that ever existed and will come to exist. Since this is an unimaginable task, His Mercy is unimaginable. Anyone who fits this description will be considered Allah by Muslims, even if that diety is called by some other name, like God Almighty, Elohim, Parmatma, Wahe Guru etc.
Start/ Origin: No. It did not start with Prophet Muhammad ﷺ, it ended with him. Prophet Muhammad ﷺ was the last Prophet of Islam, not first. Islam started with the first man Adam (peace be upon him) , who was the first Prophet of Islam. Between Adam and Muhammad 124,000 Prophets came to each nation at various times. All Prophets were sent for their people for their time alone. Prophet Muhammad ﷺ was the last Prophet hence his message is for all humanity and till the end of time.
Whose Religion are Muslims in: Muslims are in Religion of Abraham (Peace be upon him), Prophet Muhammad ﷺ was also in.
Religion: Religion of every Prophet was Monotheism. All monotheistic religions before Prophet Muhammad ﷺ were all in this religion. The religion has always been one, but its practices and laws were not necessarily the same, it could be different for each Prophet. Think of it like a constitution in a country that has a permanent structure that can’t be changed everything other clause can be changed. The basic structure of the religion was Monotheism, Truth and Justice, etc and was taught by all its 124,000 prophets. The changeable clauses were, how to pray, whether to pray once in a week or five times in a day, what kind of foods are they allowed to eat or not; such smaller issues of constitution could be different for each prophet. To us Muslims, the faith of Prophet Abraham, Moses, Jesus and all other 124k Prophets was Islam, they were all Muslims. But because of the difference in their laws and practice it gives an illusion that they were of different religions..
Monotheism, The True Religion: There is only one true God, Worship Him Alone, Seek Help from Him Only. He is called by many names, His Personal name is Allah, although that is not His Only name. The One True God’s definition is given in Quran and anyone fulfilling this criteria is Allah to Muslims, “Say: He is Allah, the One and Only; Allah, the Eternal, Absolute; He begetteth not, nor is He begotten; And there is none like unto Him.” In simple one, He has to be unique and unimaginable, if the diety can be imagined, it is no God. Who qualifies this criteria, Allah, Elohim, God Almighty, Parmatma, Wahe Guru, etc. Those who do not qualify Jesus, Rama, Krishna, Buddha, Muhammad ﷺ, Adam etc.
Sources of Islam: When debating Islam this is what you should be quoting from
1. Quran: The verbatim word of God.
2. Hadith: Saying and Actions of Prophets, divided into several sections from Sahih (authentic) to Hassan (Good) to Doubtful (Daef) or Fabricated (Mouzu). Several sections in each type of Hadith as well. The six usually agreed books of authentic Hadith of Sunnis are Bukhari, Muslim, Abu Dawood, An Nasai, At Tirmidhi and Ibn Majah.
5 Pillars: Witness/Creed, Ritual Prayer, Fasting, Charity, Pilgrimage. Witness/Creed is, “There is no God except Allah (God Almighty), and Muhammad is His Slave and Messenger” ﷺ. Ritual Prayer to be done 5 times in a day. Fasting for 30 days for a full month of Hijri Calendar (Ramazaan). Charity, 2.5% of all your savings belong to poor, give it away. Pilgrimage, to Makkah once in life if you are eligible for it (eligibility is one having means to do it).
Mosque: Central to Islam as Ritual Prayer must be offered in congregation, the place where this congregation happens is called Masjid. People are called to prayer by a person getting on the Minaret of Masjid and asking people to come for the ritual prayer. It could also be place of gathering, living, a sarai (travelers accommodation), eating, feasting, etc.
Outlook on People of Other Religions: Quran says that no religion is acceptable in eye of God Almighty except Islam, however this is not without a caveat. Quran also says that Allah can forgive anything except Polytheism. Islam has several categories of peoples based on religions they follow
1. People of the Book, Books like Pentateuch, Pslam and Gospel: Jews & Christians.
2. Monotheists: All other Monotheistic faiths apart from Judaism and Christianity.
3. Polytheists, Atheists and Antitheists
Hell: Hugely debated topic, two scholars Ibn Taimiyyah and Ibn Arabee, never agreed on almost anything except that there would be a day when Hell would be locked and its fires extinguished. Majority of classical scholars do not believe this. Anyone telling you that this has been settled is lying. Deep arguments about Quran and Islamic philosophy with loads at stake.
Jihad: strive to improve oneself. Often wrongly used in conjunction with Qital (blood letting). Qital is only a small part of Jihad. Several complicated rules are there for Qital, and it is impossible to justify killing of non combatants, innocent men, women, children and old people. This book counters every possible reason given by nut-heads to justify why they are killing innocents.
Ghazwa-e-Hind: Authenticity seriously doubtful. Clue 1. Ghazwa refers to battles that Prophet Muhammad ﷺ Himself participated, Prophet ﷺ died in Medina over 1400 years ago. so if he did not conquer India then he is never going to do it. Clue 2. Western India was Conquered in 7th century, Delhi Sultanate was established in 11th Century. Almost all scholars agree that this is a reference to past not future. 3. People with Political Interests use it forward their political goals. 4. Most Muslims do not know the difference between Jung and Ghazwa.