This paper presents finite control set model predictive control (FCS-MPC) for an isolated three-phase four-wire (3P4W) grid forming converter (GFC). The GFC uses an inductor-capacitor (LC) filter at the load terminal. The objectives are to 1) supply power to balance loads and non-linear loads, 2) supply power to unbalance loads, and 3) use a single control loop to regulate the GFC output voltage. The simulation results are presented to verify the features of isolated GFC.