But the anointing which you have received of him abides in you, and you need not that any man teach you: but as the same anointing teaches you of all things, and is truth, and is no lie, and even as it has taught you, you shall abide in him.
Read Chapter 2
Augustine of Hippo
AD 430
Then to what purpose is it that we, my brethren, teach you? If His unction teaches you concerning all things, it seems we labor without a cause. And what mean we, to cry out as we do? Let us leave you to His unction, and let His unction teach you. But this is putting the question only to myself: I put it also to that same apostle: let him deign to hear a babe that asks of him: to John himself I say, Had those the unction to whom you were speaking? You have said, His unction teaches you concerning all things. To what purpose have you written an Epistle like this? What teaching did you give them? What instruction? What edification? See here now, brethren, see a mighty mystery. The sound of our words strikes the ears, the Master is within. Do not suppose that any man learns ought from man. We can admonish by the sound of our voice; if there be not One within that shall teach, vain is the noise we make. Aye, brethren, have ye a mind to know it? Have ye not all heard this present discourse?...
You remember, brethren, that yesterday's lesson was brought to a close at this point, that you have no need that any man teach you, but the unction itself teaches you concerning all things. Now this, as I am sure ye remember, we so expounded to you, that we who from without speak to your ears, are as workmen applying culture from without to a tree, but we cannot give the increase nor form the fruits: but only He that created and redeemed and called you, He, dwelling in you by faith and the Spirit, must speak to you within, else vain is all our noise of words. Whence does this appear? From this: that while many hear, not all are persuaded of that which is said, but only they to whom God speaks within. Now they to whom He speaks within, are those who give place to Him: and those give place to God, who give not place to the devil. Ephesians 5:27 For the devil wishes to inhabit the hearts of men, and speak there the things which are able to seduce. But what says the Lord Jesus? The prince ...
But additions of other people's hair are entirely to be rejected, and it is a most sacrilegious thing for spurious hair to shade the head, covering the skull with dead locks. For on whom does the presbyter lay his hand?
You have no need You want not to be taught by any of these men, who, under pretence of imparting more knowledge to you, seek to seduce you, (ver. 26) since you are sufficiently taught already, and have all knowledge and grace in the Church, with the unction of the Holy Spirit, which these new teachers have no share in. (Challoner)
His unction teacheth you concerning all things. Unction here signifies the doctrine which they received together with the Holy Spirit or Spirit of God; in which he exhorts them to remain, as being sufficient for their instruction, and to make them avoid the new teachers of false doctrine. (Witham)