Some Key Words

Promise (epaggelia[1860]):

a legal term denoting a summons or promise - a gracious gift, not a negotiated pledge(?); a divine assurance.

Teach (didasko[1321]):

to teach by word of mouth with the intent of influencing the one taught, or to shape their will; to instill doctrine into one

Shrink away in shame (aischuno[153]):

to disfigure, dishonor, suffuse with shame; to feel shame for oneself; the sense of shame arising from something that has been done (or undone).

Practice (poieo[4160]):

to do or perform, with the focus on outcome; to act rightly, do well, to perform (applied to a promise). Not much here to support "practice" as the correct word.

Righteousness (dikaiosune[1343]):

conformity with the claims of higher authority, to all God's commands; the state of him who is as he ought to be, the condition acceptable to God, integrity, virtue, purity of life, correctness of thinking, feeling and acting.

Born (gennao[1080]):

mainly as born of man, in this case figuratively used of God's imparting His divine nature to us; in a Jewish sense, one who brings others over to his way of life - rather appropriate here.

 

Paraphrase

25 Jesus has promised eternal life, 26 which - along with His nature should be remembered in the face of deceptions. 27 We are to trust in the Word and the Holy Spirit to guide us accurately in judging what is taught us, 28 and to hold fast to those things we find true - both in word and in action - that we need not fear being ashamed of ourselves at His return. 29 All who are His, try to be like Him in their ways.

Key Verse

2:29 - we are to do our utmost to be like Him, which is to be righteous.

Thematic Relevance:	In His love for us, God has promised us eternal life, and has blessed us with the indwelling of His presence to protect us from error.
Doctrinal Relevance:	The promise of eternal life; the indwelling of the Holy Spirit to guide; the fact of His returning - all are mentioned in this brief section, passed on as simple fact.
Moral Relevance:	We must strive to abide (not to depart from, or become different) in Him. We must practice righteousness. (And lest we lose hope, we must also bear in mind that the one who says he does not sin is a liar, and the truth is not in him).
Questions Raised:	If we need no teacher, why are we given teachers? Is the anointing here spoken of to be taken as the Holy Spirit? (the use of "it has taught" seems to indicate not).

Some Parallel Verses

2:25

Jn 3:15 - whoever believes may have eternal life. Jn 6:40 - and Jesus will raise us up on the last day.

2:26

2Jn 7 - those who don't acknowledge Christ - His Godhood and His manhood - are deceiving antichrists.

2:27

Jn 14:16 - God will send another Helper, at Jesus' request. Jn 14:26 - which Helper is the Holy Spirit - who teaches all things. 1Co 2:12 - we receive the Holy Spirit that we might know what God has freely given us. 1Th 4:9 - God Himself teaches us to love the brethren (in this case, I think 'brethren' would be restricted to the church). Jn 14:17 - the Holy Spirit is the Spirit of truth, who abides with us and is in us.

2:28

Lk 17:30 - the day comes when Christ - as Son of Man - will be revealed. Col 3:4 - at which point we will be revealed with Him in glory (who's in glory, us, Him, or both?). Eph 3:12 - our confidence gives us boldness and access in faith. Mk 8:38 - His reaction to us in heaven will reflect our reaction to Him on earth - shame leading to shame. 1Th 2:19 - but our unashamed presence before God's throne will be a crown of joy to those who were our teachers.

2:29

Jn 7:18 - those who seek to glorify God have no unrighteousness. Jn 1:13 - the important birth is to be born of God. Jn 3:3 - which rebirth is a prerequisite for seeing God's kingdom. 3Jn 11 - those of God do good, those who don't do good don't see God.

New Thoughts

Given the parallel passages, it would seem that anointing is to be taken as the Holy Spirit after all. Seems rather odd to refer to Him as 'it', though. The Holy Spirit is our protection from those who would try to influence and shape us by their false words. The section starts with God's divine assurance of eternal life with Him, and ends with yet another challenging test: we are to do well, and act rightly with regard to conformity to all God's commands. This isn't practice, as NASB would have it. It's doing. The Holy Spirit is present to teach us all things (even those in heaven), that we may do all that God commands. There's really no excuse left to us. We have the tools to succeed, yet we are clearly told we will find occasion to stumble - and if we claim it's not so, we make God a liar. Not a comfortable position to be in.
Hmm, on re-reading that last verse, I see that it's not so much a test for us, as a way of identifying our fellow believers(?). i.e. - since it's impossible to fulfill the claims of righteousness without the Holy Spirit's help, if we see one who is fulfilling those claims, he must be indwelt by the Holy Spirit, and thus be born of God.
Or is it perhaps a simple reminder of the impossibility of fulfilling God's requirements without God's presence?