Serious question to christians...?

If god has a divine plan for everybody, does he plan for babies to get aborted? So the Doctor and mother are blame less. If a serial killer kills a bunch of people is it gods plan, and if so shouldnt we praise the killer for doing gods work? And why do you pray? god has already decided your faith beforehand? If you have cancer theres no reason to pray because god already decided when your gonna die. because he already knows your going to pray so why would that change the outcome