what would stop a car from firing on ether when plugs are sparking?

i have a 2007 mazda 6. 3.0 v6 5 speed. has been running fine then went out the other day to leave and it wouldnt start, it cranks over fine but no fire, fuel pump comes on for a few seconds with key, pulled a couple plugs and although they could use a replacing they are sparking, air filter is good and it has gas. I tried ether to see if it would start and nothing changed  I'm stumped!! getting a spark and spraying ether why wont it atleast try to start?? i have tried to flood it while trying to start it and there wasnt even a smell of gas and the plugs were dry afterwards. im trying to save from having to send it to a garage but im completely lost right now with what it could be.

has anyone ever had this problem or heard anything like it?
i dont think it is but is it possible that a weak spark due to worn plugs would all of a sudden stop it from running like this, even though it was running fine before? - on the other hand why isnt it getting gas?
could it be something with the security or a bad key?