In chapter 1, John dealt with 3 false claims of those who say they have fellowship with the Lord. Here in chapter 2, the apostle deals, head on, with 3 more false claims; he who says I know Him, he who says he abides in Him and he who says he is in the light. The current church has feared the error of salvation by works so much that it has fallen into the error of salvation without obedience. John makes it clear that the true believer demonstrates his relationship with the Lord through Love and obedience.
