I am not a believer of any faith, and the most common prayer you can hear from my voice is "pass the salt". However, I claim I have the right to have my own opinion on what is worth praying for.
Praying for oneself or one's beloved relatives or friends is too selfish an occupation to deserve my attention. Praying for the world in general, for world peace, or for the human race, on the other hand, sounds a bit too ambitious for any single voice. There must be a middle ground.