By the Name of Allaah, the Most Beneficent, the Most Merciful. I ask Allaah the Most Generous, the Lord of the great throne, to protect you in this world and in the Hereafter, to bless you anywhere you are, and to make you among those who are grateful when they are given, who are patient when they are tested, and who ask His forgiveness when they are sinful. Indeed, these last three are the signs of happiness. Know, may Allaah guide you to obey Him, that the religion of Ibraahiim is to worship Allaah without ascribing any partner to Him. The evidence is the Saying of Allaah Ta-aalaa,
Translation: “And I (Allaah) created not jinn and mankind except that they should worship Me (alone).” (al-Qur-aan, suurah adz-Dzaariyaat, 51: 56)
When you have known that Allaah created you so that you worship Him, then know that worship cannot be called as worship except if it is performed with having tauhiid, the same way like prayer cannot be called as prayer except if it is performed with having thahaarah (purification). When thesyirk (polytheism) enters the worship, the latter will be corrupted, the same way like hadats(impurity) when it appears while one is being in the state of thahaarah.
When you have known that if syirk is mixed with worship, it will corrupt the worship, destroy the actions of worship, and make its doer to be among the inhabitants of Hellfire, then know that the most important thing to you is to learn about it, hopefully Allaah purifies you from it, i.e., the syirk, on which Allaah Ta-aalaa says about it,
Translation: “Verily, Allaah forgives not that partners should be set up with Him (in worship), but He forgives except that (anything else) to whom He wills.” (al-Qur-aan,suurah an-Nisaa’, 4: 48)
And learning about syirk is first done by learning about its four principles that Allaah mentions in His book.
source : andyoctavian.org