If your Jeep is going into neutral while driving down the highway, get it to the dealer. That is dangerous for you, an people around you.
In the time it took to ask if it might be the battery cable you could have checked it ... no tools required.
Checking all the grounds is good advise. But since you probably don't know where they all are, you would be gambling with your safety, if that is in fact the problem.
Pulling codes is another good idea, if you think you will be able to (or want to) make the necessary repairs that they indicate.
I'm not an advocate of running to the dealer for every rattle or loose piece of trim. But when you are facing a problem that could cause an accident;
GET THEE TO A DEALER!