Thank you for your question and I understand your concern.
As Yardira suggested in the first response; adding the complete model number would be most helpful in providing model specific information and instructions.
Generally speaking, if all the electrodes quit sparking at the same time, it could have a faulty spark module or the L1 (line one) or the neutral wire has come loose or disconnected. Whenever any one burner knob is turned to the "light" position, the Line One (L1) circuit is completed to the spark module at which time the spark modules causes the sparking between the electrode and the grounded base of the burners. In order to properly diagnose the failure will require checking for a loose or disconnected wire in the circuit between the spark switches on top of each burner valve and at the spark module. Next, the voltage supply should be checked and confirmed at the spark module when the burner valve is set to the "light" positions.
Turn the gas supply off to the range before checking voltages. NOTE: I do not recommend measuring voltage unless you have experience and feel safe and confident in doing so; otherwise I recommend calling service.
So that's what I can tell you at this point. I can give you more detailed help if you could provide me with the complete model number. If you could supply me with that information I will be happy to assist you further.
If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services