The key wont turn the ignition for the jeep to start?

When you insert a key into an ignition and it won't turn could be a couple of resons. One could be that the ignition is worn out and unable to match the cuts on the key or the key was improperly cut. Many GM vehicles (and potentially others) have a steering wheen lock that will lock the ignition key. Simply turning the steering wheel in either direction will fix this.