Mixing with the Non-Muslims removes Your Religious Zeal

Question :

I am living in Jordan in a house populated mostly by Christian brothers, and we eat and drink together. Is my prayer invalid, and is my living with them permissible?

Answer:

Before answering your question, I would like to make a point: I hope that it was a slip of the tongue when you said: "I live with Christian brothers", for there is absolutely no brotherhood between the Muslims and the Christians. Brotherhood is of faith, as Allah, the Almighty, the Majestic says:

The believers are nothing else than brothers (in Islamic religion).

So if ties of blood are negated by religious differences, then how can brotherhood be affirmed when there is a difference in religion and no family ties? Allah, the Almighty, the Majestic says about Nuh and his son when Nuh said:

"O my Lord! Verily, my son is of my family! And certainly Your Promise is true, and You are the Most Just of all judges." He said: "O Nuh! Surely, he is not of your family; verily, his work is unrighteous."

Therefore there is absolutely no brotherhood between the believer and the disbeliever. Indeed, it is incumbent upon the believer not to take the disbeliever as a friend, as Allah says:
O you who believe! Take not My enemies and your enemies (i.e. disbelievers and polytheists etc.) as friends, showing affection towards them, while they have disbelieved in what has come to you of the truth (i.e. Islamic monotheism, this Qur'an and Muhammad).

And who are the enemies of Allah? The enemies of Allah are the disbelievers. Allah, the Most High says:

Whoever is an enemy to Allah, His Angels, His Messengers, Jibril and Mika'il, then verily, Allah is an enemy of to the disbelievers.

He, the Most Glorified, Most High says:
(O you who believe! Take not the Jews and Christians as Awliya' (friends, protectors, helpers etc.), they are but Awliya' to one another. And if any among you takes them as Awliya', then surely he is one of them. Verily, Allah guides not those people who are Thalimun (polytheists, wrongdoers and the unjust).

So it is not permissible for the Muslim to describe the disbeliever whatever his brand of disbelief, be he Christian, Jewish, Magian or apostate as a brother; so beware, my brother, of using such expressions.

As for the answer to the question, I say: It is necessary to avoid mixing with non-Muslims, because mixing with them causes the loss of one's religious zeal from the heart and may even lead to affection and love for them. Allah, the Most High says:
You (O Muhammad) will not find any who believe in Allah and the Last Day, making friendship with those who oppose Allah and His Messenger (Muhammad) even though they were their fathers or their sons, or their brothers, or their kindred (people). For such He has written faith in their hearts and strengthened them with Ruh (proofs, light and true guidance) from Himself. And We will admit them to Gardens (Paradise) under which rivers flow, to dwell therein (forever). Allah is pleased with them and they with him. They are the Party of Allah. Verily, it is the Party of Allah that will be successful.
Source:
Ibn Jibreen
Fatawa Islamiyah, Vol. 1 Pages 263-264-265