Car spits and sputters and backfires trys to die

But if I gas it twice it goes then it just wont start at all it will crank but wont fire.

It when I would gas it started out spitting and sputtering then it would rev up and go whenever I would gas it twice in a row real fast it would try to die at stoplights and it would even do it going down the highway.

now it wont start at all it cranks but wont start and it backfired the whole time all this was happening