We provide a numerical method in this study to solve the one-
dimensional nonlinear Klein-Gorden problem. We provide a detailed
description of the mathematical formulation process. The technique is based
on nonstandard finite differences and is explicit at three levels. The step sizes'
denominator function is nonlinear. We have provided a stability study of the
approach and shown its unconditional stability when applied to the one-
dimensional nonlinear Klein-Gorden problem. We use the suggested strategy
to two cases to demonstrate its utility