No Harm for Your Father and his Wife to Come and Stay with You
11-2-2018 | IslamWeb
Question:
As salaamu alaikum. My father remarried about 3 years ago to a Christian woman. I have zero ideas if he married her Islamically. I am only aware that he married her through the court here in USA. I live with his family, while he and his "wife" lives about 30 minutes away. He recently said that he and his wife may be staying at our place this coming summer for 3 months. I would like to know whether I will receive a punishment from Allah if they stay with us for 3 months? What should I do to avoid Allah's wrath?
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
There is no harm on you if your father and his wife come to stay with you in the house, and you do not have to investigate whether or not he married that woman Islamically.
Nonetheless, it should be noted that even though the marriage of a Muslim man with a woman of the People of the Book is in principle permissible if it fulfills its conditions, like the presence and consent of the guardian, the presence of two witnesses, and the like, but it is better for a Muslim man to marry a pious Muslim woman who would help him in the obedience of his Lord, and raise his children upon the correct creed and good morals.
For more benefit on the disadvantages of marrying women of the People of the Book and the problems that arise thereof, please refer to Fataawa 84724 and 89418.
Allah knows best.