If everything works on your range, but the oven, the most likely culprit is the igniter for the BAKE manifold. What is confusing me, though is the statement in your question where you say the "oven will light up, but never get hot". Yet, you say the oven does not ignite. Can you clarify this? In some ovens the BAKE and BROIL manifolds BOTH light when preheating, to reduce the warm up time. Once the desired temperature is reached the manifold not in use, will shut off.
In any case, on a gas range, the burners for the BAKE and BROIL manifolds use an electric glow bar type igniter. There's a separate igniter for EACH burner. When you make a bake or broil selection on your oven control, the respective igniter begins to glow. After the igniter reaches a certain current potential, the gas safety valve is opened, gas flows to the manifold, and voila! You have ignition. It can take as long as 90 seconds for the burner to ignite. What can happen over time, is the igniter becomes weak or fails. If the igniter becomes weak, it will still glow, but it never reaches the desired current potential to open the gas safety valve. The result: you end up with an igniter glowing with no ignition. And, if you're like me, you're left scratching your head wondering why the thing isn't working when it "looks" like it is. You can easily tell if the igniter is working by opening your oven door and selecting bake. Watch the oven pan in the bottom of the oven. You should see an orange glow coming from under it. It here's no glow at all, the igniter has probably failed. If there IS a glow, a current reading will tell if it's within tolerance. The following link explains more on these igniters and how to replace one:
The bake igniter is a common fail item as it gets used more frequently than the broil function. On your range both igniters are interchangeable. You can purchase replacements on line at searspartsdirect.com, repairclinic.com, or appliancepartspros.com. The part number is WB2X9154. Shop all three sites for the best price.
I hope this helps you. If my assessment of your symptoms is wrong, or if you need further assistance, please let me know.