To derive the free energy change of the universe, no assumption about the reversibility of the process is made. We solely concluded that the total free energy change of the universe during a single process is always zero because the net entropic energies of the surrounding and system balance each other out. However, we do not provide any information regarding whether the system stays in the final equilibrium configuration or not. In another word, we only calculated the total free energy change of the universe by looking at a single process from the system's and surrounding's perspectives to show how the universe preserves its energy in a process with no judgment on the total entropy change of the universe with an arrow of time in either a reversible or irreversible process. Nevertheless, we still believe any system ultimately reaches thermodynamic equilibrium with its surrounding.