Words have only the power they are allowed. That is not to say that anyone in particular is in control. Words meant to hurt can hurt, but only if who recieves them is hurt. This is the basic idea: words only have the power you, personally, ascribe to them.
Gods can hear our words. Gods are not energy, I think; rather, gods are like light, and have a dual nature (rays and particles, eg). They are affected by our words, but only as living beings (for what are gods but physical? manifestations of life?). That's why gods can't affect you if you don't believe in them; the only change they can offer is in words, and words we don't believe in just pass us by. But belief is far from simple. I still struggle with belief.