Do the gods help us if we pray to them according to Buddhism?

Will the action of praying to / worshipping gods for something be fruitful according to Buddhism? Is there any reference where a god (deva) has helped a person who has prayed to / asked help from the deva ? In Jainism, it is said that if the followers insist on praying to god, it's advised that they should pray (ask for help) only for the knowledge that leads to Nirvana. **Edit:** I asked this **NOT** because I wanted help from god or believed in god. I asked this because, Buddha said that there are heavenly beings (gods) with powers, but are themselves mortal too.. So, I just wanted to know, why Buddhists pray to those gods (I've seen many Buddhists praying to god, not all Buddhists). Is that even fruitful?