Allah , says:" Say: "Verily, my prayer, my slaughter, my life and my death are [all] for Allah, the Lord of the worlds. He has no partner: This am I commanded, and I am the first of those who submit" (Qur'an 6:162-163)
Allah , says:" Therefore pray to your Lord and slaughter [animals in His Name only]" (Qur'an 108:02)
It is reported on the authority of `Ali (ra) that he said: "Allah's Messenger (PBUH) told me four things: "Allah has cursed the one who slaughters in the name of other than Allah ; Allah has cursed the one who curses his parents; Allah has cursed the one who protects and shelters the heretic (one who innovates in religion, wrongdoer) Allah has cursed the one who alters the land-marks (or borders in order to unlawfully seize the land of his neighbour which does not belong to him) (Narrated by Muslim).
`Ali (ra) informs us that the Prophet (PBUH) told him that Allah's curse is upon every person who attempts to get nearer to Allah by slaughtering an animal in the name of other than Him, Most High, and also upon every person who curses his parents, either directly or by inciting others to do so, and upon every person who gives shelter to a heretic, and upon every person who alters the landmarks or borders in order to unlawfully seize the land of his neighbour which does not belong to him.
It is reported from Tariq Ibn Shihab (ra) that the Prophet (PBUH) said: "A man entered Paradise because of a fly, while another entered the Fire because of a fly." They asked: "How was that possible, oh, Messenger of Allah ?" He replied: "Two men passed by a people who had an idol, which it was not permissible for anyone to pass without making a sacrifice to it. They (the people) said to the first man: "Sacrifice (something)." He said: "I have nothing with which to do so." They said: "Sacrifice some-thing, even if it were only a fly," and so he did so, and they allowed him to continue on his way and so he entered the Hell-fire. Then they said to the second man: "Sacrifice (something)." But he said: "I will not sacrifice anything unless it be to Allah , the Almighty, the All-powerful," so they struck his neck (and he died) and entered Paradise." (Narrated by Ahmad)
The Messenger of Allah (PBUH) informs us in this Hadith that two men - possibly they were from the Children of Israel passed by a people who had an idol. They requested the two men to sacrifice something to it, even if it were only something small. The first of them sacrificed a fly, and because of this, he was thrown in the Hell-fire. The second, due to his strong faith and complete Tawheed, refused to do so and so they killed him and he entered Paradise.
Source: Kitab ut Tawheed.
Link: http://www.abdurrahman.org/tawheed/KTwahab/beliefs/creed/abdulwahab/frame.html
