The fundamentals of Islam are:
1. Shahada: Utterance from mouth, testimony: There is no god but ONE Almighty Allah, and Muhammad is his servant and Messenger
2. Faith- belief in Allah, Angels, holy Books, holy Messengers, the day of Judgement, Destiny, good or bad being in the hands of Almighty Allah.
3. Deeds: Offering Prayer, giving Alms, fasting in the month of Ramadhan, performing Hajj
Refer to question below for more details
It is the action of being adhered to Islam fundamentals. refer to question below.
If you mean by the word " things" the fundamentals or morals of Islam, then refer to questions below
The key beliefs are the Islam five pillars (refer to related question below). Refer to question below for the Islam main fundamentals.
If you mean the five pillars of Islam, then they are not physical pillars. They pillars of the fundamentals of the Islam religion. they are not bound by places.
By following Islam fundamentals and morals. Refer to questions below.
Following the five Islam pillars and other Islam fundamentals. Refer to questions below.
You may refer to the questions below on the basic duties of Muslims, the morals as extracted from Quran, what Muslims allowed to wear and to eat, and the fundamentals of Islam to get information on major Islam traditions.
It is not real division. It is just minor differences that do not touch basic Islam fundamentals and beliefs. Refer to question below for more information.
I wonder How do you assume that Islam is false and then you asking why?. I think you should first know the arguments and then you conclude if Islam is false or not. Anyhow, Islam is not false, Islam is the true religion. Refer to the questions below for more information on Islam fundamentals, Quran (Muslims holy book) authenticity, The scientific miracles of Quran that prove that Quran is God revelation to prophet Muhammad to call for Islam, and other Islam relevant issues.
Islam is the same everywhere. There are no different Islam religions. However, there different Islam schools as Shiites and Sunniis. However all Islam schools are similar in basic Islam fundamentals and differ only in minor details. Those who deny God oneness, prophet-hood of Muhammad (PBUH), Quran, or the Islam ritual worship, and or Quran holy book are not belonging to Islam religion even if they are Muslims on paper. Refer to question below for more information.
== == * Yes, a Muslim does belong to the Islamic religion.The follower of Islam is called Muslim. == ==
Islamic fundamentalism simply means following and practicing the fundamentals of Islam. Every Muslims should be fundamentalist. Just like every mathematician should follow and practice the fundamentals of Mathematics, until he does that, he is not a good mathematician. Similar, until a Muslim follows the basic and fundamental principles of Islam, he is not a good Muslim.