Hello,
Often this is caused by a clogged idle air control valve. The idle air control valve will allow air into the throttle body through a little port, and that can get full of debris that gets sucked into the throttle body.
That is very common, but there are many other causes that may be. This could be an ignition switch, bad fuel pump, or many other concerns.
My advice with start and stall conditions is always have diagnostics performed. It will likely save time and money.
RepairPal Certified shops can diagnose and repair your 2003 Jeep Liberty. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.