One who says, "I know him," and doesn't keep his commandments, is a liar, and the truth isn't in him.

 Here was John's problem. In the Greek world he was faced with people who saw God as an intellectual exercise and who could say, "I know God" without being conscious of any ethical obligation whatever. In the Greek world he was faced with people who had had an emotional experience and who could say, "I am in God and God is in me," and who yet did not see God in terms of commandments at all. 