Her sister lost her faith and became a Darwinist
5-4-2011 | IslamWeb
Question:
My sister has disbelieved in Islam she does not believe in religion she has been watching a lot of the theory of evolution I am afraid shaitan has taken over her heart I don’t think she believes in ALLAH too. My parents had sent her to a kafir university and this is the result. Me and my other sister are (All praise be to ALLAH) believing people and my parents also frequently pray namaz how ever not to insult them but they have been poor in teaching us ISLAM. My sister has told me about her disbelief I can not bear it!! 1) Should I tell my parents about this I am afraid my mother will fall very ill hearing this news. However she might be able to force her to read namaz 2) Any thing in my power I can do ANYTHING! any dua any surah to recite so that ALLAH might change her heart INSHALLAH. 3) what steps do we take to turn her to the religion. Is it purely namaz should we do it with force?
Answer:
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.
If what you mentioned is true that your sister does no longer believe in religion and that she has committed what takes her out of the fold of Islam, then this is a very serious matter. This clarifies the importance of the warnings issued by the scholars and the Du’aah (callers to Islam) against the mistake which many Muslims make by being lenient in sending their children to study in non-Muslim universities, and then such a painful result happens. For more benefit, please refer to Fatwa 126158.
Therefore, it becomes an obligation to advise your sister and remind her of Allaah and warn her of Allaah’s severe Punishment if ever she dies as an apostate. In this regard, you may make use of some means of calling an apostate which are clarified in Fatwa 87672. Also, you may benefit from Fataawa 83754 and 86254 which clarify the falsehood of the theory of evolution.
On the other hand, there is no specific supplication or Surah (Chapter of the Quran) to recite in order to guide her, but you may supplicate with any suitable supplications. It might be that if you fulfill the obligation of advising her, she will take heed and be guided to the truth and then you will not need to mention this matter to her parents.
However, if she persists in her misguidance, then you may inform your father about the matter without informing your mother if it is feared that she will be (greatly) affected by it, so that your father would fulfill his obligation towards his daughter and present her to the scholars so that they would try to remove the falsehoods and illusions from her mind.
It should be noted that if a person apostates, his prayer is of no avail to him/her while he/she is still on his/her disbelief. Allaah Says (what means): {And what prevents their expenditures from being accepted from them but that they have disbelieved in Allaah and in His Messenger.} [Quran 9:54] Hence, the first thing that an apostate should be asked to do is to re-embrace Islam.
Finally, we ask Allaah to guide her to His right Path and enable her to repent and return to Him.
Allaah Knows best.