The non-gospel that mixes the grace of God with law ("Paul and James are basically saying the same things" asserts the false gospel) began in the first century when the Judaizers harassed
Paul's converts, telling them that justification by faith was not enough to be saved. Remarkably, the Judaizers are alive and well today, taking many forms, the most notable—as far as I can tell—being Stephen E. Jones and his acolyte Thomas Kissinger.