Question: If G-D hears our prayers why don't we also see them being answered?
Answer: One has to construct a vessel to contain the blessing. After praying for health one has to see a doctor; after praying for a job, one has to go out and look for it, thereby creating a vessel in which G-D's answer and blessings can manifest themselves.
From The Works And Talks Of The Lubavitcher Rebbe Shlita
Published by Vaad Hanochos Hatmimim
On Good and Evil
Good is eternal. ``Evil'', however, pos-sesses no true existence, being only the concealment of good - just as darkness is not a positive force but merely the absence of light. So the evil of the past has long dissipated or has been subli-mated and utilized positively, while the
good lives on and accumulates.
Thus, our every positive act carries the monumental weight of generations past. Our every good deed hits home with the combined force of the countless ac-complishments of all who came before us.
From an address by the Rebbe Shlita, Passover 1958