How old is your battery? It is possible the battery is bad or going bad or the starter/solenoid is bad. Take the starter out and go to the local auto parts store and have it tested. They can test the battery in the Jeep before you go through the trouble of taking the starter off and can probably "test" the starter while still on the Jeep as well, but the bench test for the starter gives better results and is more accurate in my experience.
The Jeep is gone, I had to have a truck.