1 John 2:20
 But you have been anointed by the Holy One, and you all have knowledge. (ESV)
If you watch enough late night preaching you are likely to hear some preacher talk about the "anointing." The anointing of the Holy Spirit is portrayed as some mystical, almost unattainable, except by the very holy, thing to pursue and ultimately possess. If someone is viewed as successful in ministry many will say, "Wow, they must have a powerful anointing." This kind of portrayal of the anointing of God's Spirit does a great disservice to many believers who feel intimidated by this way of thinking and feel that they are somehow deficient because they obviously don't have a special anointing, or at least not as powerful as brother so and so.
John is writing to believers who also had been beaten up by false teaching. They were made to think that somehow they were deficient in their understanding. The false teachers claimed that they and they alone had special knowledge. With this "so-called" special knowledge came an air of arrogance. The fact is these false teachers had no ground to stand on. Their teaching was false and their knowledge was not special.
John says some very encouraging words in this verse. First of all, he says YOU have been anointed. That is a plural YOU. He is speaking to all of the believers, not some of them. The anointing John speaks of is the Holy Spirit. All believers have the Holy Spirit, not some. There is teaching in the body of Christ that those who belong to Jesus Christ now must ask the Holy Spirit to come into them. This flies in the face of what John says in this verse. Even the Apostle Paul addressed this issue.
 You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him. (ESV)
John not only tells us that we all have the anointing of the Holy Spirit, but he says, "and you all have knowledge." Again, these false teachers had tried to make the believers feel as if they were missing out on knowledge. But John reminds them that they have the Holy Spirit and therefore they have knowledge. The very Spirit of God was dwelling in them and giving them knowledge. And the same is true for us.
If you are a believer you have the anointing. You do not need to seek it. And you have knowledge. The question is, what are you going to do with what you have?