Idolatry

Idolatry: the major sin of idolatry or polytheism. the Bible strongly prohibits all form of idolatry. It refers to the deification of anyone or anything other than the singular GOD.

Idolatry is also "associating partners" with GOD, giving His characteristics to others beside Him, or not believing in GOD's characteristics based on the Ten Commandments. 

"You shall have no other gods before me. You shall not make for yourself a graven image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them or serve them; for I the Lord your GOD am a jealous God, visiting the iniquity of the fathers upon the children to the third and the fourth generation of those who hate me, but showing steadfast love to thousands of those who love me and keep my commandments." (Exodus 20:3-6)

• bowing down or falling down before a stone (kaba) is considered worshipping this stone, as is forbidden in the Ten commandments.
• bowing down or falling down before a statue or image is worshipping the statue or image.
• also the love for material things (car/phone/money/house etc) can be idolatry if this love for material things, is greater then your love to serve GOD.
• making men more important then GOD or making onself more important, (Egotism), too is idolatry.

the Cardinal sins:

The deadly sins, also known as the capital vices or cardinal sins, is a classification of vices (part of Christian ethics) that has been used since early Christian times to educate and instruct Christians concerning fallen humanity's tendency to sin. In the currently recognized version, the sins are usually given as:

• Murder / Wrath / Rage
• Rape
• Beastiality
• Pedophilea / Incest
• Lust / Greed / Envy,  for power and wealth
• Idolatry / Egotism / Pride