1Jn 2:20-2:24 - Safety of truth and Holy Spirit

Calvin

2:20: Having given the warning, John moves assure them that they are not being reprimanded, only reminded. Paul did much the same. (Ro 15:14-15 - assured of their goodness and knowledge, yet he reminds them to minister.) We tend to tune out those who speak poorly of our knowledge, so John opens his readers' ears by assuring them that their knowledge is recognized, and rather gives them the greater cause to excel. He reminds, rather than instructing in basics, he stirs up that which already was to bring it to greater heights. "All things" should be considered restricted to the topics at hand, the anointing referring to the Holy Spirit's work in giving us the truth. Our knowledge is not our own.
2:21: Whatever deceptions Satan may try, we can know the truth by the guidance of the Holy Spirit, knowing that "no lie is of the truth."
2:22: The examples held forth here are not the exclusive definitions of lying and antichrist, but the epitome of their type - the grossest example. Denying any part of Christ - His godhood, His manhood, His grace or His power - is equally an activity of antichrist spirit. Good list of early heresies here, by the way. This includes the works approach that teaches that we can redeem ourselves by our actions. Taking away anything from Christ is denying Him. And in denying the Son, they have also denied the Father whose Son He is. Here, John states some very core tenets of faith - that Christ is the only form in which God's essence has or can be seen by man. The full glory of God would blind us by its brilliance, but in His Son, He has made His glory approachable. (Heb 1:3 - Christ the representation of God's nature.) While Father and Son are indeed of one eternal essence, this is not directly discussed here, and yet there is proof here. John's attention is on the fact that we are called to seek God in and through Christ alone. All other approaches amount to idolatry, (Col 2:9 - for the fullness of the Godhead is in Him.)
2:23: "There is no right confession of God except the Father be acknowledged in the Son." This has always been the way of God's revelation, even in times when those He revealed Himself to knew not the source.
2:24: John points to the fruit of obedience. Perseverance differs from obstinacy in that the former requires sound reasoned doctrine as a precondition, whereas the latter simply refuses to change from an opinion once formed. We must begin with certain and reliable truth, else perseverance will be mere obstinacy. Here comes both fruit and the test for sound doctrine: if it remains in us, we remain in God - if the doctrine is sound, it will unite us to God, and tend to hold us there.

Matthew Henry

2:20-2:24: John encourages his readers of their constancy amid the dangers. We are blessed as anointed ones, appointed as subordinates to our Lord. The text can be taken to indicate either the Holy Spirit or Christ as the source of the blessing. (Rev 3:7 - Christ is the "Holy One".) By this anointing we are given understanding of all things pertaining to "Christ and His religion." (Jn 14:26 - this is what the Holy Spirit was sent to do.) There is a danger that the less anointed might be turned from true Christianity to acts of an antichrist spirit. [This seems dubious on the surface. Had they any anointing, they were of Christ, and He has not lost a one.] John clarifies that he is not belittling their knowledge, but rather presuming its presence in them. Their knowledge of truth made them fit to discern error, as "no lie is of the truth." The use of fraud was roundly denounced by the apostles as an unfit means of propagating truth. Unfortunately, later ages ignored the warning. "The result of them appears in the infidelity of our age; the detection of ancient pious frauds and wiles has almost run our age into atheism and irreligion." The father of lies tends towards falsehoods relating to the person of Christ, in spite of the attestations of heaven, hell and earth to His truth. Those who embrace such falsehoods are thereby made "direst enemies to God," rejecting His Son, and thereby rejecting Him, for He Himself declares the relationship, and the means of reconciliation. (Jn 6:27 - God the Father has set His seal [given authority to] the Son.) "Truth is older than error." As such it should not be traded in for something new and novel. Clinging to this truth gives the advantage of continued union with God. The truth in us allows the severing of sin's hold upon us as it unites us to Christ. (Jn 15:3-4 - Christ's word has cleansed us, it remains for us to abide in Him.)

Adam Clarke

2:20: The anointing is symbolic of the Holy Spirit's governance of the Church, and of His blessing its appointed officers. (Ps 45:7 - God anointed David with joy beyond all others of his time.) It also completes the type of the oil of anointing from Moses' day. (Ex 30:23-25 - by specific rules, the oil of anointing was made, to be considered as holy. Ex 29:7 - This oil was poured over the head of the ones appointed as priests to consecrate them to God's service.) He reveals to us all that is needful to know for salvation, the excessive knowledge of the Gnostics being fruitless. An alternative would be to take this as knowing all men (i.e. - what they were truly about.) This would fit with the general sense of the letter in warning against false teachers and such. [The argument seems a trifle thin, hanging on wordings that aren't actually there.]
2:21: Because they know the truth, it is reasonable to write to them of testing all teachings by the truth they already know, for it makes of them sound judges.
2:22: Some denied Jesus' godhood. This includes denial of His miraculous birth, His being the Son of God, and/or God the Father being His Father. The Jews denied the whole of it. The Gnostics denied the birth, claiming the infusion of some angelic being instead.
2:23: In denying the Sonship of Jesus, the Father also is denied.
2:24: We are to continue in all the doctrines of Jesus - His birth, passion, death, resurrection, etc. This will serve to confirm our being among God's children by faith in His Son, and our fellowship with them.

Barnes

2:20: The anointing alludes to the sealing of kings and priests (1Sa 10:1 - David anointed as king, 1Sa 16:13 - and again. Ex 28:41 - Aaron and sons anointed as priests, Ex 40:15 - the anointing appointed for the succession of priests,) and symbolizes the giving of the gifts of the Holy Spirit to those anointed, we being the princes and priests of the New Testament church (Rev 1:6 - we have been made a kingdom of priests, Rev 5:10 - reigning on the earth, 1Pe 2:5-9 - a royal priesthood.) These gifts serve to keep us free from error and apostasy. The Holy Spirit gives us to know all that is essential to religion. (Jn 16:13 - He discloses what He hears from Christ, and what is to come, 1Co 2:15 - thus giving us the means to appraise all things.) The 'all things' cannot be taken as extending to knowledge of history, science, etc. It refers solely to the things of religion, not to some miraculous increase in intellect at conversion, nor to new revelations - such revelations having been completed in the Word, nor a newfound ability to perceive things imperceptible to the senses beforehand. It does refer to a greater understanding of the truth and its implications, an elimination of any doubts regarding the truth of the truth sufficient to make them willing to risk their lives in its service, and an expanded acquaintance with more of the truth. That this is true is seen in the testimony of Scripture (1Co 2:14-15 - the truths of the Spirit require spiritual understanding, Jn 16:13-14 - such understanding comes as it is disclosed to us by the Holy Spirit,) in the testimony of our own experience - the non-religious find no beauty in the things of religion unless they be converted, thus changing their perceptions; that change may prove to be so quick in developing as to be unaccountable other than by Holy intervention. This interventions can also be seen in the grasp that the otherwise uneducated will show in the subject of religion (Jn 7:15 - they marveled at the ability of uneducated Jesus to teach so well, Ac 4:13 - as well as Peter and John.) Finally, that this is true is seen in the fact that those who grasp it are willing to die for it.
2:21: The writing is not to be taken as an admonishment of a lack of understanding, but will be fruitful because of their understanding. Regardless of any plausibility, perceived benefit, or temporary goodness, no lie can be founded in the truth - nor can any of the truth be founded in a lie. All doctrine should be tested against the revealed truth, not against our perceptions of that doctrine.
2:22: The extreme example of those who denied Jesus' Godhood by clever explanations is held out as an example of something clearly false to those who have true knowledge no matter how cleverly presented. How, precisely, this group denied Jesus' Godhood is not specified, but showed them to have all the characteristics of opposers of God. Such denied the special role of God as Father to the Son, and Jesus as Son to the Father, to get the Son wrong requires that the Father be misunderstood as well. (Mt 11:27 - none knows the one without the other, Jn 5:23 - to dishonor the Son dishonors the Father as well.)
2:23: Those who deny the Son have no friendship with the Father, who has declared Christ the only way to reconciliation. (Heb 1:2-3 - He appointed the Son as heir and representative.)
2:24: Given the importance of the truth's influence upon our state, we ought never to let it depart - these truths being those which have ever been taught regarding the way of salvation, and of true unity with God.

Wycliffe

2:20: Through the anointing we are able to detect teachers of falsehood even if they do not depart the church. There is a contrast here between the Antichrist and his antichrists vs. Christ and His christs (anointed ones). All things speaks particularly to the differentiation of true and false teachings in the church.
2:21: Two reasons for writing - their knowledge of truth and that no lie is of the truth - form a bond between writer and reader. Every lie is alien to the truth.
2:22: The attack is against Gnosticism, not Judaism, as the argument is against those who denied the truth of God and man united in Jesus, not against those who denied He was the Messiah spoken of in the OT (Ac 5:42 - The apostles teach of Jesus as Messiah.). To deny Jesus as Christ is to deny Him as Son is to deny God the Father (Mt 11:27 - none know the Father except they know the Son.)
2:23: To deny the Son is to forfeit the rights of adoption by God (Jn 1:12 - receiving the Son brings the right to be God's children). This is a living relationship that is accepted or rejected, not some badge of honor.
2:24: Abiding in the foundational truths keeps us abiding in the Son and so in the Father.

Jamieson, Fausset & Brown

2:20: The anointing of the Holy Spirit come from Christ (Jn 1:33 - upon whom the Holy Spirit descended, Jn 3:34 - which Holy Spirit He gives without measure, Jn 15:26 - and which also bears witness to Him, Jn 16:14 - disclosing to us all Jesus has for us) the Holy One (Ac 3:14 - whom they disowned in favor of a murderer) of God (Mk 1:24 - acknowledged as such even by demons.) Only by Christ's anointing are we able to resist those anointed by Antichrist, and remain in the Father and the Son. "The Spirit poured on the Head [Christ] is by Him diffused through the members." Just like the oil dripping down on Aaron's beard. By the anointing we know all that is needful to resist Antichrist's seductions and live a Christian life in whatever measure we have the Spirit.
2:21: We know the truth regarding Father and Son, and can detect lies as being opposed to this truth.
2:22: Those who deny the central truth of Christ - that He is the Christ, is the Son of God, and both came and died in the flesh - move in the anointing of Antichrist. (Mt 11:27 - Those who know the Son have the Father revealed to them.)
2:23: All who deny the Son lose the Father. Those who recognize and openly confess the Son have as their abiding portion by fellowship the Father, as well.
2:24: We are urged, then, to retain the truth of Jesus, allowing it to take root within us. "Having taken into us the living seed of truth concerning the Father and the Son, we become transformed into the likeness of Him whose seed we have."

New Thoughts

I find my thoughts going in two directions here. As always, I find the warnings of great import. We need to be checking what goes on in our church with what the Word has said. We need to be certain of our foundations, eliminating false conceptions and standing firm on the truth. Scripture is ever our proof text - an unerring guide. The Holy Spirit will certainly direct us - by memory, study, or other means - to the proof we need. If we allow Him to work in us. God is not one to force Himself in where He's not wanted. With that in mind, I find it rather exciting to look back on some of the definitions here. We are given to know by experience the reality at the basis of our belief - the essence of our faith. We are given to know all things. Hey, it may not include the sciences and such like, but come on! It does include the mysteries of heaven! That's stunning enough to keep anybody humbled. Then there's the second half of v23: the one who celebrates with public praises, declares openly, speaks out freely about Jesus the Son of God, lays hold of, clings to, and is joined closely to the Father and the Son. I don't know about visions of gold dust, or other such mysticalities. The gifts of the Spirit, I know. The test of the fruits I'm thankful for, although I'd prefer to stand up better under those tests myself. But the freedom of praise and worship! This is our badge, our seal, so long as we can keep the flesh away. Where the praise and worship is earnest, it cannot but draw us to God. Where the voice that sings is giving voice to the heart, there is one who has joined closely to the Father. Will we see His glory? We've seen it in Christ. God, I pray You help us to test ourselves, that we need not fear Your judgement later. I pray that You help us to get past our easily impressed senses, and seek the deeper sharing that You offer to us, the communion of Father and child, the joy of brotherhood with Christ, the heartfelt conversations of our spirit and Your Holy Spirit. Do we want more? You bet. But we don't want more of just anything, we want more of true religion, of Your truth, of what You want to bestow upon us. Keep us hungry, Lord, but keep us ever vigilant that no error creep in to our love of You. Help us to remember that You've provided us with the sole means of approaching Your glory - Your Son. Forgive us, Lord, if we've sought other paths to Your throne, and keep us ever on the path of Your will.