1Jn 2, 21-23 Every lie is alien to the truth

(1Jn 2, 21-23) Every lie is alien to the truth
[21] I write to you not because you do not know the truth but because you do, and because every lie is alien to the truth. [22] Who is the liar? Whoever denies that Jesus is the Christ. Whoever denies the Father and the Son, this is the antichrist. [23] No one who denies the Son has the Father, but whoever confesses the Son has the Father as well.

(CCC 91) All the faithful share in understanding and handing on revealed truth. They have received the anointing of the Holy Spirit, who instructs them (Cf. 1 Jn 2:20, 27) and guides them into all truth (Cf. Jn 16:13). (CCC 92) "The whole body of the faithful… cannot err in matters of belief. This characteristic is shown in the supernatural appreciation of faith (sensus fidei) on the part of the whole people, when, from the bishops to the last of the faithful, they manifest a universal consent in matters of faith and morals" (LG 12; cf. St. Augustine, De praed. sanct. 14, 27: PL 44, 980). (CCC 93) "By this appreciation of the faith, aroused and sustained by the Spirit of truth, the People of God, guided by the sacred teaching authority (Magisterium),… receives… the faith, once for all delivered to the saints…. The People unfailingly adheres to this faith, penetrates it more deeply with right judgment, and applies it more fully in daily life" (LG 12; cf. Jude 3). (CCC 2482) "A lie consists in speaking a falsehood with the intention of deceiving" (St. Augustine, De mendacio 4, 5: PL 40: 491). The Lord denounces lying as the work of the devil: "You are of your father the devil,… there is no truth in him. When he lies, he speaks according to his own nature, for he is a liar and the father of lies" (Jn 8:44). (CCC 678) Following in the steps of the prophets and John the Baptist, Jesus announced the judgement of the Last Day in his preaching (cf. Dan 7:10; Joel 3-4; Mal 3:19; Mt 3:7-12). Then will the conduct of each one and the secrets of hearts be brought to light (cf. Mk 12:38-40; Lk 12:1-3; Jn 3:20-21; Rom 2:16; 1 Cor 4:5). Then will the culpable unbelief that counted the offer of God's grace as nothing be condemned (cf. Mt 11:20-24; 12:41-42). Our attitude to our neighbour will disclose acceptance or refusal of grace and divine love (cf. Mt 5:22; 7:1-5). On the Last Day Jesus will say: "Truly I say to you, as you did it to one of the least of these my brethren, you did it to me" (Mt 25:40).