mercy

Dear Sheikhs, Assalamu Alaikum wa Rehmatullahe wa Barakatuh! Allah Almighty is merciful, His mercy is prevailing everything. Why then to fear Allah, as is said by many people and in some quotations of the Holy Book? I do not go wrong at all but just wish some clarifications for my inner irritations. Jazakum Allahe Khairan! Fe Aman Allah!

I am concerned about animal sacrafice. Do most anmials suffer during this time or is it a quick and painless action to aviod the innocent creature less pain?  I had heard that muslims take pride in the pain of others (animals), surely this must not be true. Please clarify.

Dear scholars, As-Salamu `alaykum. My parents have a pet cat. It is very sick now. They are planning on “putting it down”. Is this kind of mercy killing allowed in Islam? Jazakum Allah khayran.