Islam is based on belief and the Divine Laws. We have already discussed some of the Divine Laws, including its pillars, the fundamental principle of the religion.
The Islamic creed and faith are inclusive of systematic belief in what has been revealed by Allah through the Prophet Muhammad (peace and blessings be upon him) such as verdict, Divine Laws, heavenly information, about the unseen and other similar aspects. It also includes the Sunnah or the traditions of the Prophet Muhammad (peace and blessings be upon him) and his way of life.
The Islamic belief is based on six fundamentals, as mentioned here:-
(1) To believe in Allah
(2) To believe in the angels.
(3) To believe in the Divine Scriptures.
(4) To believe in the Messengers and Prophets of Allah.
(5) To believe in the Day of Judgment.
(6) To believe that everything, whether good or evil, should occur according to the Divine Predetermination and Predestination of Allah.
We can now discuss about some of these fundamentals in detail:

DETAILS OF FUNDAMENTALS OF THE ISLAMIC FAITH:

(1) BELIEF IN ALLAH:
Believing in Allah forms the basic concept of all fundamentals of Islamic belief and most significantly, a noble knowledge in Islam.
To explain it further, the belief in Allah refers to the firm acknowledgements in the existence of Allah and that He is the Lord of the Universe and Master of everything.
He is the only Creator and Controller of the entire universe, therefore, Allah is the only deity worthy of worship, Who has no partner(s). He is infallible and possessed all the qualities as signified in His meaningful Names and perfect Attributes.
He is the only One, Perfect and Majestic, Who is free from all discrepancies, defects and deficiencies. He has no resemblance in any way or form with any of His creatures.
This concept of Islamic faith, which is universal in nature, should remain embossed in the heart of every human being. Every person is born with an instinct and a natural inclination to believe in Allah without possessing prior knowledge or thoughts.
Thus, a person lives with the same inclination until he/she tends to change it with purpose to embrace the original Islamic belief with which the human being was born and saves himself / herself from leading a life with wrong belief.
Allah said,
 فِطْرَتَ اللهِ الَّتِي فَطَرَ النَّاسَ عَلَيْهَا
“Allah s Fitrat (i.e. the nature or Allah s Islâmic Monotheism), with which He has created mankind.” [Surah Ar-Rum 30:30]
The phrase ‘fitrata Allahi’ in the above verse refers to the religion of Allah, i.e. Islam. Therefore, every person is bound to return to the Islamic fold and seek Allah’s help from any difficulties – whether material or spiritual.
A person, whether a monotheist, a polytheist, or a disbeliever, if falls in distress or be in a difficult situation, he/she is bound to discard away all superstitions or the imaginary thinking. Rather, keep only the belief in Allah in his/her mind, as this forms the natural inclination of a person’s mind.
Therefore, he/she should revert spontaneously to Islam to seek help from Allah urging Him to take him/her out from distress or difficulty.
In other words, a person is born with a natural inclination to believe in the only pure religion of Allah, i.e. Islam.
This could be exemplified with the following narration of the facts of life. A person, whose natural disposition is to love the Creator, readily tends to acknowledge His existence, Who being the Only One worthy of worship.
This phenomenon of life occurs during the birth of every person whose body with a natural propensity for accepting food. Similarly, the heart of a newborn is bestowed a capacity to accept the natural inclination to belief in Allah. Besides, the newly born soul would be prompted to acknowledging of faith in Allah.
The Prophet Muhammad (peace and blessings be upon him) has described about this fact saying,
« كُلُّ مَوْلُودٍ يُولَدُ عَلَى الْفِطْرَةِ فَأَبَوَاهُ يُهَوِّدَانِهِ أَوْ يُنَصِّرَانِهِ أَوْ يُمَجِّسَانِهِ »
“Every child is born upon the Fitrah (i.e., the natural religion of Allah which He made for humanity), it is only his parents who turn him into a Jew, a Christian or a Zoroastrian.” [Al-Bukhari and Muslim].
This Hadith indicates that every newborn comes in this world with an inclining heart to accept the natural religion of Allah (i.e. Islam). This is why the Prophet Muhammad (peace and blessings be upon him) did not say “turn him into a Muslim” while speaking about conversion of a person to religion.
It is because of this fact that, following religions other than Islam is considered as conversion from the original and basic religion (i.e. Islam) due to the reasons as mentioned in the Hadith above.
On the other hand, the parents of a newborn child turn him/her away from the original and natural religion to follow other faiths such as Jews, Christian, and Zoroastrian among other religions, which contradict to the natural inclination of humanity.
Moreover, all the right thinking people openly support the natural religion, which Allah has made for the humankind. It is the mind of those people, which reflects as a significant sign of belief in Allah. Any contemplating mind would reach to a conclusion after obtaining knowledge that this world inhabited by various creatures that existed on the heaven, mountains, oceans, the humans, animals, the agricultural produce or the inorganic substance, etc, that there is a definite Creator of this whole universe – Allah, the Almighty – Glory Be to Him.
In this context, it becomes a duty of any sensible person with sound mind to believe in only the truth and not in any hypothetical theories. The three viewpoints explained here could serve a person to understand and reach to a valid conclusion:
(1) To assume that the appearance of all the creatures that exist in this world is a coincidence and developed without the work of a definite creator.
This viewpoint is hypothetical and hence unacceptable by any sensible and sound human mind. Any right thinking person with a common sense would fail to understand that something exists without a creator or made.
On the other hand, it is worth contemplating that the creatures that has been existing are created in the most systematic and pre-planned order. They co-exist in total harmony with one another.
Therefore, to consider that the existence of things in this world a coincidence is impossible.

(2) To Assume That the Creatures Came Into Existent on Their Own.
This is also an invalid theory. A person with common sense could find it impossible to accept this hypothesis, because it is not possible for anything to exist in this world on its own.
The hypothesis only contributes to an unending debate as who came first: a chick or an egg, as it is a fact that none of the two were existent until created by a Creator.
How is it possible for something non-existent to be created on its own?
Thus, these two types of viewpoints on the creation of the universe stood discarded. Therefore, we reach to a conclusion based on a belief, which is valid, sound and above all acceptable to the common sense. This is the third viewpoint based on Islamic principle as mentioned here briefly:-

(3) There is A Definite Creator of This Universe; And All the Creatures That Exist On Earth or Elsewhere.
Allah is the Only Creator, Who created everything. He is immortal -- neither was ever nonexistent nor will expire.
Allah stated in the Qur’an about this absolute evidence based on strong reasoning and acceptable to every sound mind and sensible person:
 أَمْ خُلِقُوا مِنْ غَيْرِ شَيْءٍ أَمْ هُمُ الْخَالِقُونَ
“Were they created by nothing, or were they themselves the creators?”[At-Tur 52:35].
The above verse of the Qur’an indicates that they had neither been created without a Creator, nor created by themselves. Thus, it is clear from this that He is Allah Alone, Who created them all, as every creature must have a Creator.
Similarly, everything should have a trace proving its own effect and functioning, which is produced by a producer. It would be appropriate to say that anything manufactured should have its manufacturer and a thing achieved should be as a consequence of a performance by someone.
The above interpretation of the creation of the universe is based on a valid reasoning and hence acceptable to every person having sound mind and common sense.
Therefore, whoever has doubts or fails to understand this simple explanation on the issue in discussion needs to develop a commonsense, before engaging in such debates.
This was also agreed by a number of eminent non-Muslims. Their viewpoints were elucidated in a book titled ‘Allah Manifests In The Scientific Age” authored by 30 world’s renowned scientists, astronomers and the physicists.
This book could serve as best reference material to understand the creation of the universe for the intellectuals or the layman and to study Islam and be a believer.
Meanwhile, an atheist or a disbeliever should necessarily have studied Islam superficially, who appeared from a category scholars either with mediocre knowledge or the pseudo-intelligent.
Therefore, such people, who grope in the dark with their false belief, would loss an opportunity to reach to a natural religion that Allah has created for the humankind. Thus, they never attain the truth and for that matter a true faith.
Similar to the aforementioned book, there is another publication called “The Human Does Not Exist alone” translated into Arabic language under the title “The Knowledge calls To the True Faith”.
Mr. Chris Morison, former president of Science Academy in New York and the Chairman of the American Institute in New York City is the author of this book.
Mr. Morison had also served in several other capacities such as the executive member of the Board of National Research Council of the United States of America, a fellow in the American Museum for Natural History and a life member of the British Royal Institute.
In his book Mr. Morison wrote that the progress of the humans is based on his/her congenital character, a natural inclination and a constant consciousness toward an obligation that lead him to search for a true faith – that is Islam, the religion of Allah.
He further wrote that the abundance of spirituality and piety lift the human being systematically to a lofty position and at one stage, he/she becomes able to communicate with Allah.
As for supplicating or invoking Allah, seeking His help in abundance is a natural thing. The simple prayer, which a person performs, is to approach his Creator and to seek His closeness and proximity.
He wrote that the atheists lack the characteristics such as gravity, generosity, decency, ethics and the virtue.
He further said in his book that without true faith, the civilization would plunge into bankruptcy. The people would live in anarchy and a chaotic situation. The system of life lacks the control with everyone would tend to act either as regulator or a governor. There would be confusion in running the state of affairs; things would deteriorate from bad to worst with work machinery coming to a standstill.
Therefore, the best way is that we must adhere to true faith believing the fact that there is Allah and we must love Him.
He said that the man has a limited capacity to comprehend that he would not be able to grasp the infinite nature of this universe. Therefore, it is appropriate on the part of man to believe in the existence of the Creator, Who brought everything into existence from the smallest particles such as atoms to galaxies and the sun.
Mr. Morison said despite the proliferation of humankind and the man since his creation spread to everywhere, it is understood that he is motivated to turn on seeking help from One Who is loftier, mightier and the most powerful.
This clearly signifies to the fact that Islam is the natural religion and therefore the science must agree to it.


EVIDENCES OF THE ONENESS OF ALLAH AND BELIEF IN HIM:
There are several perceptible and palpable evidences, which clearly indicate to the Oneness of Allah and belief in Him. The following are some of the examples that prove to the Oneness of Allah:

ANSWERING THE INVOCATION:
The raising of hands towards the Heavens by the several oppressed and depressed invoking prayers to Allah seeking help. Allah responds to their prayers and relieves them from their difficult situation by removing harm and hardship, accordingly.
As every Muslim is well aware that Allah ascertains and answers their supplication and invocation, which is proven in several instances.
Allah said,
 وَقَالَ رَبُّكُمْ ادْعُونِي أَسْتَجِبْ لَكُمْ إِنَّ الَّذِينَ يَسْتَكْبِرُونَ عَنْ عِبَادَتِي سَيَدْخُلُونَ جَهَنَّمَ دَاخِرِينَ
“And your Lord said, ‘Invoke Me, [i.e. believe in My Oneness (Islâmic Monotheism)] (and ask Me for anything) I will respond to your (invocation). Verily! Those who scorn My worship [i.e. do not invoke Me, and do not believe in My Oneness, (Islâmic Monotheism)] they will surely enter Hell in humiliation!’” [Ghafir 40:60].
Allah said,
 أَمَّنْ يُجِيبُ الْمُضطَرَّ إِذَا دَعَاهُ وَيَكْشِفُ السُّوءَ 
“Is not He (better than your gods) Who responds to the distressed one, when he calls Him, and Who removes the evil.”[An-Naml 27:62].
Allah mentioned in the Qur’an about the instances of the Prophets from whom He accepted their invocation, for example Allah said,
 وَنُوحًا إِذْ نَادَى مِنْ قَبْلُ فَاسْتَجَبْنَا لَهُ فَنَجَّيْنَاهُ وَأَهْلَهُ مِنْ الْكَرْبِ الْعَظِيمِ 
“And (remember) Nûh (Noah), when he cried (to Us - i.e., Allah) aforetime. We listened to his invocation and saved him and his family from great distress.” [Al-Anbiyaa 21:76].
Allah said,
 إِذْ تَسْتَغِيثُونَ رَبَّكُمْ فَاسْتَجَابَ لَكُمْ أَنِّي مُمِدُّكُمْ بِأَلْفٍ مِنْ الْمَلاَئِكَةِ مُرْدِفِينَ 
“(Remember) when you sought help of your Lord and He answered you (saying): "I will help you with a thousand of the angels each behind the other (following one another) in succession." [Al-Anfal 8:9].
Similarly, there are several other evidences available in the Sunnah of the Prophet Muhammad (peace and blessings be upon him) indicating to the answering of the supplications from those invoked to Allah.
In a Hadith recorded by Al-Bukhari, Anas bin Malik narrated:
Once in the lifetime of the Prophet Muhammad (peace and blessings be upon him) the people were afflicted with drought (famine). While the Prophet Muhammad (peace and blessings be upon him) was delivering the Khutbah (religious sermon) on a Friday, a Bedouin stood up and said, "O, Allah s Apostle! Our possessions are being destroyed and the children are hungry; please invoke Allah on our behalf (for rain)".
After listening the request, the Prophet Muhammad (peace and blessings be upon him) raised his hands in supplication.
The time when Prophet Muhammad (peace and blessings be upon him) raised his hands in prayer there were no clouds in the sky. By Him in Whose Hands my soul is! As soon as he lowered his hands, clouds build up like the size of mountains, and even before he got down from the pulpit, I have witnessed the drops of water falling on the beard of the Prophet (peace and blessings be upon him).
It rained the whole day and that continued for the two consecutive days and until the next Friday. The same Bedouin o