بسم الله الرحمان الرحيم
All Praise is due to Allah سبحانه و تعالى, may Peace and Blessings be upon Messenger of Allah صلى الله عليه و سلم, his progeny and his companions رضي الله عنهم
After 11th September and 7/7 attacks, many Muslims have developed fear of the disbelievers so much that many of them have changed their names from Muhammad to Moe and Bilal to Billy just avoid being arrested by the police. Is this way we are commanded to be? Are we allowed to be fearful of the disbelievers when we are on the Truth whilst they are misguided?
Allah سبحانه و تعالى categorically tells us that it is only shaytaan, who wants us to fear his allies so do not fear them,
إِنَّمَا ذَٰلِكُمُ الشَّيْطَانُ يُخَوِّفُ أَوْلِيَاءَهُ فَلَا تَخَافُوهُمْ وَخَافُونِ إِن كُنتُم مُّؤْمِنِينَ
“It is only Satan that suggests to you the fear of his allies. So, do not fear them, and fear Me if you are believers.”
Al Haafidh Ibn Kathir رحمه الله writes in his Tafsir, “Shaytaan threatens you with his friends and tries to pretend they are powerful and fearsome.” 
Al Hasan رضي الله عنه and Al Suddi رحمه الله comment on this ayah by saying, “The meaning of the fear of his (shaytaan) allies means the hypocrites who forsake and sit (in their homes) and do not fight the disbelievers. As for the Friends of Allah, they do not fear when they are told to fear them (allies of shaytaan).” 
Mujahid bin Jabr رحمه الله said, “The believers fear (khawf) the disbelievers.”
Then Allah سبحانه و تعالى tells us, “…So, do not fear them, and fear Me if you are believers.”
Yet again, Al Haafidh Ibn Kathir رحمه الله beautifully writes, “If Shaytaan brings these thoughts to you, then depend on Me (Allah سبحانه و تعالى) and seek refuge with Me. Indeed, I shall suffice you and make you prevail over them” 
Imam Abu Ja‘far Ibn Jarir Al Tabari رحمه الله writes, “Do not be in awe of their group with your obedience to Me and obey My orders. We will force upon you victory and success. However, only fear Me and have Taqwa of committing acts of disobedience against Me and going against My commandments.”
So, the stronger your faith becomes, the weaker the fear in your heart will be of Satan’s allies, and the weaker your faith becomes, the stronger the fear in your heart will be of them. And one can increase his Imaan by the obedience of Allah سبحانه و تعالى and staying away from His disobedience. The very reason we are in this phase because our Imaan is weakened and it is so because have stopped following the Sunnah of RasuluLlah صلى الله عليه و سلم.
This fear develops when one is embarrassed of his Islam being known to people and the reason for that is because he doesn’t have trust in Allah سبحانه و تعالى that whatever He has chose for him i.e. Islam is the best. Thus the person develops lack of confidence and starts concealing his religion from others when he must openly declare and practice as a Muslim.
Let me share a story with you, just after he accepted Islam, ‘Umar رضي الله تعالى عنه wanted his acceptance of Islam to get noticed so when he saw that the Muslims were being tortured, he wanted to be like them. So he went to Abu Jahl’s house and knocked his door. Abu Jahl said, “Welcome Ibn al-Khattab, welcome!” (he didn’t know that ‘Umar رضي الله تعالى عنه was a Muslim yet). ‘Umar ibn al-Khattab رضي الله تعالى عنه said, “I became Muslim.” Abu Jahl said, “What?! Don’t do so!” ‘Umar رضي الله تعالى عنه said, “Well I did!” Abu Jahl slammed the door on his face. ‘Umar رضي الله تعالى عنه said, “This is not what I am looking for.” Then he went to someone else’s house and the same thing happened. There was somebody who was watching what ‘Umar رضي الله تعالى عنه was doing and he went to ‘Umar رضي الله تعالى عنه and said, “It seems that you want people to know that you have become a Muslim.” ‘Umar رضي الله تعالى عنه said, “Yes!” The man said, “You see that man over there, go to him and tell him that you have become a Muslim that’s what you have to do.” He was pointing towards Jamil ibn Mu’ammar al-Jumahi. ‘Umar رضي الله تعالى عنه went to him, and said, “O’ Jamil, I have become a Muslim.” ‘AbduLlah ibn ‘Umar said, “I was watching my father, when he told Jamil, he immediately stood up, dragged his Izaar and walked briskly towards the Ka’bah where people were meeting said, ‘Ya Quraysh ‘Umar embraced Islam! Umar embraced Islam! Umar embraced Islam!’” In fact, the narrations say Jamil wasn’t saying that but he was saying, Umar Saba’!” which was a derogatory term used against Muslims. ‘Umar was trying to correct Jamil by saying, “Bal Aslamt Bal Aslamt” when Jamil was saying, “’Umar Saba’.” The mobs just attacked from every direction and ‘Umar رضي الله تعالى عنه was between them, fighting for himself and was being hit from every side. ‘Umar رضي الله تعالى عنه grabbed ‘Utbah bin Rabi’ah, a noble man of Quraysh, sat on top of him and stuck his fingers in his eyes! So, ‘Utbah screamed so everybody backed up. ‘AbduLlah رضي الله تعالى عنه said, “When he released ‘Utbah, and walked away, they attacked him again. Whenever they would attack him, ‘Umar would grab the noblest man in front of him and stick his fingers in his eyes until they would back off and that kept on happening again and again. Eventually, he could not fight anymore, so he sat down and people were hitting him from everywhere and then he said, ‘If we were but 300 strong, you would either leave it for us or we would leave it for you.’” This happened in Battle of Badr where Muslims were 313* and they defeated the kuffar. When ‘Umar رضي الله تعالى عنه became Muslim, there were 40 Muslims in total Allahu A’alam if that included Muslims who migrated to Abyssinia. Then ‘Umar رضي الله تعالى عنه went to Dar al-Arqam and asked Prophet صلى الله عليه وسلم, “Aren’t we on the right path, whether we live or die?” The Prophet صلى الله عليه وسلم said, “Yes!” ‘Umar رضي الله تعالى عنه said, “Then why should we hide?” So, Prophet صلى الله عليه وسلم agreed with ‘Umar رضي الله تعالى عنه and he arranged Muslims in two ranks and the Prophet صلى الله عليه وسلم was standing in between these two ranks. One of the ranks was headed by ‘Umar رضي الله تعالى عنه and the rest by Hamzah رضي الله تعالى عنه and they marched down the streets of Makkah declaring “Ashhadu an La Ilaha IllaLah wa Ashhadu ana Muhammadur RasuluLlah” This only happened when ‘Umar and Hamzah رضي الله تعالى عنه became Muslims and the difference between their acceptance was 3 days. When they reached Ka’bah, the people were depressed like never before and that day, ‘Umar رضي الله تعالى عنه was given the name al-Farooq by Prophet صلى الله عليه وسلم: the criterion of haqq and baatil.
* There is a difference of opinion on the exact number some narrations say 313,others 315 whilst others say 319 Allah سبحانه و تعالى knows best.
Sadly, most Muslims do not follow the footsteps of ‘Umar رضي الله عنه rather they try to integrate or blend in with the lifestyle of the unbelievers just to save themselves from being ‘harassed’ because they are Muslims. They try to please them whilst gaining the anger of Allah سبحانه و تعالى. ‘A’ishah رضي الله عنها wrote to Mu’awiyah رضي الله عنه: ‘Salamun ‘alayk. Amma ba’d, I have heard the Messenger of Allah صلى الله عليه و سلم say, ‘Whoever gains the Pleasure of Allah by the anger of the people (i.e. thereby gains their anger), Allah suffices him of the people’s troubles. And whoever gains the pleasure of the people by the Anger of Allah (i.e. in the process he gains His Anger), then Allah leaves him to the people.’ Wa-Salaamu ‘alayk.’  This is a stern warning going against the commands of Allah سبحانه و تعالى to make His creation happy. An example of such act would be not going for a fardh prayer because one is in an ‘important’ meeting in his office and people might get disturbed or he might feel awkward whilst leaving the room. A person in this or a similar situation should think to himself, “Do I want to seek the pleasure of Allah or keep on being fearful of the disbelievers’ attitude towards my Islam? Which action is more worthy?”
No matter how much a person tries, he will never be able to please everyone. As Imam al Shaf‘i رحمه الله said, “’There is nobody except that he has someone who loves him and someone who hates him. So if that’s the case, let a person be with the people who are obedient to Allah سبحانه و تعالى!’ (- as they love and hate for the Sake of Allah and they are not unjust)  Since you can’t have everyone happy with you at a time so why not seek the Pleasure of Allah سبحانه و تعالى at the expense of having others displeased?
In conclusion, we must realise and understand that by being afraid of the non-Muslims’ response on our strict allegiance to Islam will not gain us anything. Rather we will lose in this world and in the next. In this world we might not even be able to make this people happy by compromising on our Deen and in the next, we will have lost Paradise due to Allah سبحانه و تعالى being Angry with us. So I’d like to finish this article by saying, “So, do not fear them, and fear Me (Allah سبحانه و تعالى) if you are believers.”
And indeed Allah سبحانه و تعالى knows best.
 Surat `Al ‘Imran, ayah 175
 Tafsir Ibn Kathir
 Tafsir Al Qurtubi
 Tafsir Al Tabari
 Tafsir Ibn Kathir
 Tafsir Al Tabari
 Sunan Al Tirmidhi, hadith is sahih
 Hilyat Al Awliyaa’
 Surat `Al ‘Imran, ayah 175