I have a 2001 Pontiac Montana the fuel pump and fuel filter is good the motor cranks but won't start don't know what is wrong with it?

Fuel - Air - Spark, all needed for the engine to run. Check to see if you are geting a spark at the plugs by pulling one and, while holding it against a good ground, have someone turn the key and watch for the spark at the plug. If OK, then see if fuel is flowing. Does the pump energize when you turn the key to "on"? Does fuel flow from your fuel line at the engine (carb or fuel rail), if fuel injected, check the rail and injector pressure. If fuel is not the problem, the look for blockages in airflow at both the intake and exhaust sides. Good luck.