Bakara 221:

• Ve müşrik kadınlarla, onlar iman etmedikçe evlenmeyin. Çünkü mümin bir kadın, müşrik bir kadından - bu sizin hoşunuza gitse de- daha hayırlıdır. Ve müşrik erkeklerle, onlar iman etmedikçe kadınlarınızı evlendirmeyin. Zira mümin bir erkek, müşrik bir erkekten - bu sizin hoşunuza gitse de- daha hayırlıdır. Böyleleri sizi ateşe davet ederken, Allah(cc) sizi cennete ve O'nun izniyle mağfirete davet ediyor. İşte Allah(cc) mesajını insanlara bu şekilde açıklıyor ki, düşünüp ders alsınlar.
  (
  The reason why the believers have been prohibited from marrying musrhik spouses is that `they invite you to the Fire'. This means that such marriage might mislead the Muslim spouses to the ways of shirk, for the relations between husband and wife are not merely sexual but spiritual and cultural as well. It is possible that the Muslim spouse may influence the mushrik spouse and his or her family and their offspring in favour of the Islamic way of life. But it is equally possible that the mushrik spouse may imbue the Muslim spouse, his (or her) family or their offspring, with the spirit and ways of shirk. Most probably as a result of such a marriage, a mixture of Islam and un-Islam will be bred in such a family. A non-Muslim might approve of this, but a Muslim cannot. One who sincerely believes in Islam can never take such a risk merely for the sake of the gratification of his lust. He would rather suppress his passions than do anything that might mislead him to disbelief, blasphemy and shirk or, at least mislead his progeny. ET
  
  )