Ruling on working for disbelievers if the workplace is mixed and they talk about matters of their religion for hours
Question

I work in a company whose founders and owners are Christians, as are most of the workers. It is my income regarded as haram and unlawful? Will I be called to account for not calling them to enter Islam? I try to give a good image of Islam in my attitude and dealings; is this sufficient? Is my mixing with them and listening to them talk about matters of their religion, such as fasting and the service in the church, without objecting to it, something for which I will be called to account? I try to be present whilst ignoring this talk of theirs, but we are only human and they talk for hours in front of me.
Praise be to Allah.Firstly: working for a non-Muslim
It is permissible to work for a disbeliever in jobs other than being a servant.
It says in al-Mawsu`ah al-Fiqhiyyah, 19/45: The jurists are agreed that it is permissible for a disbeliever to serve a Muslim.
They are also agreed that it is permissible for a Muslim to be hired by a disbeliever for specific work that he takes on, such as sewing a garment, building a house, cultivating land and so on, because `Ali (may Allah be pleased with him) was hired by a Jewish man to bring him water, and he was paid one date for every bucket. He told the Prophet (blessings and peace of Allah be upon him) about that, and he did not object to it. Moreover, the one who is hired to do a job can always find work with someone else.
They are also agreed that it is not permissible for a Muslim to be hired by a disbeliever to do something that is not permissible for him to do, such as pressing grapes for wine, tending pigs, and so on. End quote.
It is stipulated that he must adhere to Islamic rulings with regard to greeting others, offering condolences, offering congratulations, and so on.
Shaykh Ibn `Uthaymin (may Allah have mercy on him) was asked: Someone works with disbelievers; what advice can you give him?
He said: We advise this brother who works with disbelievers to seek a job where there are none of the enemies of Allah and His Messenger, who follow religions other than Islam. If that is possible, then that is what he should do, but if it is not possible, then there is no blame on him, because he has his job to do and they have their jobs to do.
But that is on condition that there is no love for them in his heart and he does not want to take them as close friends, and that he adheres to the teachings of Islam with regard to greeting them, returning greetings and so on. Also, he should not attend their funerals, celebrate their festivals or congratulate them on those occasions.
End quote from Fatawa ash-Shaykh Ibn `Uthaymin, 3/39.
Secondly:
The basic principle is that it is prohibited to work in a mixed environment, because of the many evils and transgressions that result from that, as has been explained previously in the answers to questions no. 1200, 50398 and 106815.
The matter is more serious if that is mixing with the disbelievers, because there is a great deal of immorality and illicit relationships among them, and they talk about such matters. If, in addition to that, they talk about their religion and acts of worship for hours, then this – by Allah – is a serious problem. So save yourself and flee from this job, and look for a job where there is no mixing, for preserving faith takes precedence over preserving wealth.
For the ruling on calling these people to Islam, please see the answer to question no. 131777.
And Allah knows best.