'Admit' in the Bible

But the natural [unbelieving] man does not accept the things [the teachings and revelations] of the Spirit of God, for they are foolishness [absurd and illogical] to him; and he is incapable of understanding them, because they are spiritually discerned and appreciated, [and he is unqualified to judge spiritual matters].

If we say we have no sin [refusing to admit that we are sinners], we delude ourselves and the truth is not in us. [His word does not live in our hearts.]

If we [freely] admit that we have sinned and confess our sins, He is faithful and just [true to His own nature and promises], and will forgive our sins and cleanse us continually from all unrighteousness [our wrongdoing, everything not in conformity with His will and purpose].

For many deceivers [heretics, posing as Christians] have gone out into the world, those who do not acknowledge and confess the coming of Jesus Christ in the flesh (bodily form). This [person, the kind who does this] is the deceiver and the antichrist [that is, the antagonist of Christ].

If anyone comes to you and does not bring this teaching [but diminishes or adds to the doctrine of Christ], do not receive or welcome him into your house, and do not give him a greeting or any encouragement;