Corruption of Mankind
Shaykh Saalih bin Fawzaan bin Abdillaah al-Fawzaan
Originally Produced By Daru Ahlil Athar
Allaah has created his creation so as to worship Him and has prepared for them that which will aid them in this from His provisions. He ta'ala says
"And I (Allaah) created not the jinns and humans except they should worship Me (Alone). I seek not any provision from them (i.e. provision for themselves or for My creatures) nor do I ask that they should feed Me (i.e. feed themselves or My creatures). Verily, Allaah is the All-Provider, Owner of Power, the Most Strong."
The soul, if it is left upon its fitrah (natural state) affirms Allaah's divinity and has love for Allaah, worships Him alone, and does not ascribe partners to Him.
However the Shayaateen from the Jinn and the Ins (mankind) corrupts and deviates it from that with what they reveal to one another by way of beautification in speech and deceptions. Tawheed is centered in the fitrah. Shirk is foreign and inserted into it. Allaah ta'ala says:
"So set you (O Muhammad) your face towards the religion of pure Islamic Monotheism Hanifa (worship none but Allaah Alone) Allaah's Fitrah (i.e. Allaah's Islamic Monotheism), with which He has created mankind. No change let there be in Khalqilaah (i.e. the Religion of Allaah Islamic Monotheism), that is the straight religion, but most of men know not" 
The Messenger of Allaah (sallallaahu 'alaihi wa sallam) said "Every child born is born upon the fitrah, however his parents make him into a Jew or a Christian or a Pagan" So the root of the children is Tawheed.
The religion was Islaam from the time of Aadam (alaihi salaam) and until those who came after him from his progeny for many generations.
Allaah ta'ala says:
"Mankind were one community and Allaah sent Prophets with glad tidings and warnings" 
The first occurrence of shirk and deviance upon the aqeedah was with the people of Nuh (alaihi salaam)
"Verily, We have inspired you (O Muhammad SAW) as We inspired Nuh (Noah) and the Prophets after him;" 
Ibnu Abbaas said "There was between Aadam and Nuh (alaihima salaam) ten generations, all of them upon Islaam"
Ibnul Qayyim said "This comment (of Ibnu Abbaas) is clearly correct for the reading of Abi ibn Ka'b of the verse "So they differed and then Allaah sent the Prophets"
Allaah's statement affirms this when He says
"Mankind were but one community (i.e. on one religion - Islaamic Monotheism), then they differed (later), and had not it been for a Word that went forth before from your Lord, it would have been settled between them regarding what they differed" 
The sending of the Prophets was due to the differing from that which they were upon from the correct religion. Just as the Arabs were upon the religion of Ibraaheem (alaihi salaam) until 'Amru bin Lahee al-Khazaa'ee surfaced and changed the religion of Ibraaheem. He erected idols in the land of the Arabs and in the land of al-Hijaaz in a specific manner until they were worshipped besides Allaah and shirk began to spread in the Holy lands and its surrounding it until Allaah sent His Prophet Muhammad, the seal of the Prophets (sallallaahu 'alaihi wa sallam).
He called the people to Tawheed and to following the path of Ibraaheem and fought the true Jihaad until the creed of Tawheed and the path of Ibraaheem was returned to and the idols were destroyed. Allaah completed with him His religion and completed His favor upon all of the worlds. This methodology continued through out the noble generations from the beginning of this Ummah until ignorance began to spread in the later generations. Many (false) ideologies infiltrated it and shirk returned to many of this Ummah because of callers to misguidance and building structures over the graves in an effort to glorify the Awliyyaa' and Saaliheen (righteous individuals) claiming love for them until monuments were built over their graves.
They were taken as idols of worship besides Allaah by many ways this included du'a, seeking assistance, slaughtering, and sacrifice at their locations.
They called shirk Tawassul (means of drawing closer to Allaah thru worship) with the righteous and expression of their love for them and not worship of them as they claimed.
They have forgotten that this was the excuse of the pagans before them when they said,
""We worship them only that they may bring us near to Allaah" 
Even with this shirk falling upon the mankind past and present you found the majority of them believing in Tawheed ar-Ruboobiyyah but ascribing partners to Allaah in their worship as Allaah ta'ala says:
"And most of them believe not in Allaah except that they attribute partners unto Him"
They do not deny the existence of their Lord; only a small number of mankind did, such as Phir'awn, atheists, and the communists present in this era. Their denial is from their being blatantly arrogant. They are still compelled to testify this inside (their hearts) as Allaah says:
"And they belied them (those Ayah) wrongfully and arrogantly, though their own selves were convinced thereof" 
Their intellects know full well that every creation has to have a creator, every thing in existence has to have one who brought it into existence, and the order of this great disciplined and complicated matter has to have one who has power over it , wise, and maintains its order possessing all knowledge of it. Whoever denies these facts then he is either void of any intellect or blatantly arrogant and has limited his intellect and suppressed himself and this of course has not goal to it.
 Adh-Dhaariyaat – 56-58
 ar-Room -30
 In the two saheehs on the authority of Aboo Hurairah
 an – Nisaa 163
 Yunus - 19
 az-Zumar - 3
 an-Naml - 14