Question Summary:
We recently had some fellow Muslims over our house for dinner. My mother is a catholic and she bought some cakes …

Question Detail:

We recently had some fellow Muslims over our house for dinner.  My mother is a catholic and she bought some cakes from the grocery store.  she did not know that it contained gelatin in them.  the guest were caught by my mom reading the ingridents trying to see what was in them.  they told my mom it had gelatin in it and could not be eaten.  further more, they did not allow my mom to put it on the tabel.  my mom felt very hurt by this.  this is not the first time this has happened.  we caught looking in our cabnits, and reading ingridents of other food products.  my question is that as muslims and being guests of ours, should they be allowed to do this.  it is very insulting, and because this is about the fifth time they have done this, my mom is getting angry. 
second question,  i have been told we cannot eat food products with gelatin in them.  know this family has told us we cannot eat anythings that cantain enzymes from dead cows.  how can we possibly know if it has enzymes in it if it isn't in the ingrideients, and this has been a main factor for them not eating most of our food, while being our guests.  please explain.

Answer :

In the name of Allah, Most Gracious, Most Merciful
Assalaamu `alaykum waRahmatullahi Wabarakatoh
There are two issues in this: 
a)      Muslims being particular in halal and haram.
b)      Etiquettes of guests and good character.
Both issues are equally important. Muslims must be particular in consuming halal and abstain from haram. Islam is all about good character and etiquettes. Indeed, there is more emphasis in Shariah on good character and etiquettes. The emphasis is greater in relation to non-Muslims. When non-Muslims interact with Muslims, Muslims should behave and act responsibly. Our good character and conduct will attract them to Islam. Conversely, our bad behavior and insensitivity towards them will be a bad reflection on Muslims and Islam. The conduct of your Muslims guests in front of your mother was unfortunate. They lack wisdom and diplomacy. They could have conducted themselves better than just being rude. Our advice to you is if such people cannot behave, you do not have to invite them and unnecessarily bear with their rude conduct. You need to make your mother comfortable and win her over to Islam. Muslims with bad character will be an obstacle to that.
And Allah knows best
Wassalam
Mufti Ebrahim Desai
Darul Iftaa, Madrassah In'aamiyyah