If people had no emotions and sentiments, there would have been no test. People have great love for their children. If a person did not love his own son, then there would have been no test. People love their children, family and entire household. This is the test. If people were stone-hearted, there would have been no test at all. God has placed the strong sentiment of love in every human being. 
This love is for whom? It is for God, not for one's family. 
"Those who believe love God most." (2:165)

Those who direct this emotion of love to their children, family and business set up partners with God. Your emotion of love is for God, not for humans. If your emotion of love is not for God, you will be regarded as those who set up partners with God. You will face the same end as those who set up partners with God. People think that only worshipping stones is an example of setting up partners with God. This is a big misconception. 
What is shirk?
The exalted human emotions of love and fear are meant only for God Both these emotions should be directed only to God. The Quran says: Copy Arabic text "Those who believe love God most." (2:165)
The other verse is: "[Believers] stands in awe of none but God." (9:18)
One who has fear of and love for 'other than God', then he sets up partners with God. This is a very serious matter. Many people say: "Alhamdulillah we do not set up partners with God, because we do not worship idols!" There is no greater misconception than this.