Question:

 Dear Dr. Nabulsi,
 Why can a Muslim man marry a non-Muslim woman but a Muslim woman can't marry a non-Muslim man?

Answer:

 Dear brother,
 Assalamu Alaikum,
 The answer should be: because Allah permitted the first case and prohibited the second one. The wisdom behind this is that when a Muslim man marries a non-Muslim woman (Christian for example), he believes in Prophet Jesus and the Book sent down on him which is the Gospel.
However, when a Muslim woman marries a non-Muslim man she believes in Prophet Muhammad (PBUH) and the noble Quran that was sent down on him, but her non-Muslim husband doesn't believe in them, and here problems arise.
In addition, man has qawama (guardianship and authority) over woman so if a Muslim man married a non-Muslim woman he could raise his children as Muslims but the other way round is not possible.
 Best regards