All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
There is no doubt that saying that "all religions are good'' is an act of disbelief. Whoever believes this, is a non-Muslim and is out of the fold of Islam, as in reality she is denying the saying of Allaah (interpretation of meaning): {And whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers.}[3:85], and denying His saying {interpretation of meaning): {Religion in the sight of Allaah is (nothing but) Islam}[3:19]. Believing as well that 'the saying of the Christians that Jesus in Son of God' and other fallacies, is not very important, is no doubt that this is disbelief which takes the person out of the fold of Islam as well. Rather, it is an obligation to believe that the Jews and Christians and other polytheists are disbelievers. Allaah says (interpretation of meaning): {Surely, in disbelief are they who say that Allaah is the Messiah, son of Maryam (Mary)….}[5:17].
Allaah further says (interpretation of meaning): {…, and the Christians say: Messiah is the son of Allaah. That is their saying with their mouths, resembling the saying of those who disbelieved a foretime. Allaah's Curse be on them, how they are deluded away from the truth! They (Jews and Christians) took their rabbis and their monks to be their lords besides Allaah (by obeying them in things which they made lawful or unlawful according to their own desires without being ordered by Allaah), and (they also took as their Lord) Messiah, son of Maryam (Mary), while they (Jews and Christians) were commanded [in the Tauraat (Torah) and the Injeel (Gospel)) to worship none but One 'Ilaah (God - Allaah) Laa ilaaha illa Huwa (none has the right to be worshipped but He).}[9:30-31]. Allaah also says (interpretation of meaning): {Surely, disbelievers are those who said: "Allaah is the third of the three (in a Trinity)".}[5:73]. So how can it then be said that this matter is not very important. Her saying that what matters is ones actions and not belief, is a complete misguidance. Allaah says about the polytheists (interpretation of meaning): {And We shall turn to whatever deeds they (disbelievers, polytheists, sinners, etc.) did, and We shall make such deeds as scattered floating particles of dust.}[25:23]. Allaah also says in another verse (interpretation of meaning): {And nothing prevents their contributions from being accepted from them except that they disbelieved in Allaah and in His Messenger.}[9:54]. In another verse Allaah states (interpretation of meaning): {The example of those who disbelieve in their Lord is [that] their deeds are like ashes which the wind blows forcefully on a stormy day; they are unable [to keep] from what they earned a [single] thing. That is the straying far away from the Right Path}[14:18]. There are many verses which show that the deeds of the disbelievers become void and that they do not benefit them because of their wrong belief. So how can it be said that what matters is ones actions and not belief?
We advise you to call this woman to Islam with wisdom and soft words; you can use beneficial tapes and books about this subject. But if you notice that she rejects what you say, or that you are not qualified to call her to Islam and fear about yourself from her misconceptions, then it is better to cut relations with her, as Allaah says (to His Prophet ), (interpretation of meaning): {So do not let yourself perish over them in regret}[35:8]. Allaah also says (interpretation of meaning): {And do not be grieved, [O Muhammad ], by those who hasten into disbelief. Indeed, they will never harm Allah at all. Allah intends that He should give them no share in the Hereafter and for them is a great punishment.}[3:176].
Moreover, the Prophet said: "Do not keep company except with a believer, and only a pious person should eat your food." [Abu Ya'laa] So there is no good in befriending her as long as she is in this state. Please refer to Fatwa: 86405 regarding residing in a non-Muslim country.
Allaah knows best.