Bismillah
Insh a Allah turning the light on this thread, those topics are really good exercise.
Regarding the word believing, Karbala, we are talking about those who believer according to Ayahs from Quran, If you read the Quran and follow the positions when Allah Described those who believe, it will be very clear that the word refers to those who believe in Allah as follows:
"And of humankind are some who take (for worship) others besides Allah as rivals (to Allah). They love them as they love Allah. <b>But those who believe, love Allah more (than anything else). </b>If only, those who do wrong could see, when they will see the torment, that all power belongs to Allah and that Allah is Severe in punishment." (Quran 2: 165)
"And when you have divorced women and they have fulfilled the term of their prescribed period, do not prevent them from marrying their (former) husbands, if they mutually agree on reasonable basis. <b>This (instruction) is an admonition for him among you who believes in Allah and the Last Day</b>. That is more virtuous and purer for you. Allah knows and you know not." (Quran 2:232)
