One who says, "I know him," and doesn't keep his commandments, is a liar, and the truth isn't in him.
and the truth is not in him; there is no true knowledge of God and Christ in him; nor is the truth of the Gospel in his heart, however it may be in his head; nor is the truth of grace in him, for each of these lead persons to obedience. The Ethiopic version renders it, "the truth of God is not with him";  :-.