What does the Bible say about liars?

The Bible specifies that a liar, in the context of faith, is someone who denies that Jesus is the Christ. In 1 John 2:22-23, it is stated, 'Who is a liar? He that denieth that Jesus is the Christ. He is Antichrist that denieth the Father and the Son.' This highlights the severity of denying both the truth of Christ and the relationship between the Father and the Son. John emphasizes that accepting the Son is essential to having the Father; therefore, to deny Christ is to reject the foundational truth of the Christian faith.