Al Wala Wal Bara
https://en.wikipedia.org/wiki/Al_Wala%27_Wal_Bara%27Al-wala' wa-l-bara' (Arabic: الولاء والبراء‎‎) is an Arabic term meaning "loyalty and disavowal". Al-wala' wa-l-bara' is referred to by some as holding fast to all that is pleasing to God, and withdrawing from and opposing all that is displeasing to God; namely the Kafirs(un-believers) who are to be hated:
Koran 9:29: "Make war on those who have received the Scriptures [Jews and Christians] but do not believe in Allah or in the Last Day. They do not forbid what Allah and His Messenger have forbidden. The Christians and Jews do not follow the religion of truth until they submit and pay the poll tax [jizya] and they are humiliated."
http://quranicverse99.tripod.com/islamicways/id15.html"One of the aspects of iman is al wala wal baraloving and hating for the sake of Allah Alone. It is one of the most important beliefs of Islam after Tawheed. Allah says in His Book:
Let not the believers take disbelievers for their friends in preference to believers. Whoever does this has no connection with Allah unless you are guarding yourselves against them as a precaution. Allah bids you to beware of Himself. And to Allah is the journeying. (Surat Ali Imran 3:28)
The reason why al wala wal bara is so important in Islam is because, if it is taken into practice, it can remove all the characteristics of Jahiliyyah from the Muslim Ummah, it guarantees the preservation of the Ummah, and it distinguishes the believer from the disbeliever. When one loves and hates for Allahs sake only, they are raised degrees higher than those who love, hate, and act based on their own desires or fake gods or for other meaningless things."
"Enmity for the sake of Allah signifies showing anger towards those who oppose Allah, His Messenger (sallallahu alaiyhi wa sallam), His deen, and the believers. It is to struggle and fight against them in order to uphold and spread the way of Allah and His Messenger (sallallahu alaiyhi wa sallam). There is a brilliant example of this in Ibrahim (alaiyhis-salaam), as narrated by Allah in the Quran:
There is a good example for you in Ibrahim and those with him when they told their people: Surely, we disassociate ourselves from you and all that you worship beside Allah. We have done with you. And
there has arisen between us and you enmity and hate forever until you believe in Allah Alone. (Suratul Mumtahanah 60:4) "
http://www.bing.com/search?q=Al+Wala+Wal+Bara&go=Submit+Query&qs=bs&form=QBLHMake no mistake, al Wala Wal Bara includes
hatred of persons, as opposed to hatred of satanic doctrines that deceive and destroy men, such as Christian hatred of Islam.