'Liar' in the Bible

You are of your father the devil, and you want to do the desires of your father. He was a murderer from the beginning, and does not stand in the truth because there is no truth in him. Whenever he speaks a lie, he speaks from his own nature, for he is a liar and the father of lies.

and you have not come to know Him, but I know Him; and if I say that I do not know Him, I will be a liar like you, but I do know Him and keep His word.

May it never be! Rather, let God be found true, though every man be found a liar, as it is written,“That You may be justified in Your words,And prevail when You are judged.”

If we say that we have not sinned, we make Him a liar and His word is not in us. Cross references: 1 John 1:1 : John 1:1f; 1 John 2:13, 14 1 John 1:1 : Acts 4:20; 1 John 1:3 1 John 1:1 : John 19:35; 2 Pet 1:16; 1 John 1:2 1 John 1:1 : John 1:14; 1 John 4:14 1 John 1:1 : Luke 24:39; John 20:27 1 John 1:1 : John 1:1, 4 1 John 1:2 : John 1:4; 1 John 3:5, 8; 5:20 1 John 1:2 : John 19:35; 1 John 1:1 1 John 1:2 : John 15:27; 1 John 4:14 1 John 1:2 : John 10:28; 17:3; 1 John 2:25; 5:11, 13, 20 1 John 1:2 : John 1:1 1 John 1:2 : John 1:4; 1 John 3:5, 8; 5:20 1 John 1:3 : John 19:35; 2 Pet 1:16; 1 John 1:1 1 John 1:3 : Acts 4:20; 1 John 1:1 1 John 1:3 : John 17:3, 21; 1 Cor 1:9 1 John 1:4 : 1 John 2:1 1 John 1:4 : John 3:29 1 John 1:5 : John 1:19; 1 John 3:11 1 John 1:5 : 1 Tim 6:16; James 1:17 1 John 1:6 : John 8:12; 1 John 2:11 1 John 1:6 : John 8:55; 1 John 2:4; 4:20 1 John 1:6 : John 3:21 1 John 1:7 : Is 2:5 1 John 1:7 : 1 Tim 6:16 1 John 1:7 : Titus 2:14 1 John 1:8 : Job 15:14; Prov 20:9; Rom 3:10ff; James 3:2 1 John 1:8 : John 8:44; 1 John 2:4 1 John 1:9 : Ps 32:5; Prov 28:13 1 John 1:9 : Titus 2:14 1 John 1:10 : Job 15:14 1 John 1:10 : John 3:33; 1 John 5:10 1 John 1:10 : 1 John 2:14 end of crossrefs

The one who says, “I have come to know Him,” and does not keep His commandments, is a liar, and the truth is not in him;

Who is the liar but the one who denies that Jesus is the Christ? This is the antichrist, the one who denies the Father and the Son.

If someone says, “I love God,” and hates his brother, he is a liar; for the one who does not love his brother whom he has seen, cannot love God whom he has not seen.

The one who believes in the Son of God has the testimony in himself; the one who does not believe God has made Him a liar, because he has not believed in the testimony that God has given concerning His Son.