1 John 2:27
 But the anointing that you received from him abides in you, and you have no need that anyone should teach you. But as his anointing teaches you about everything, and is true, and is no lie—just as it has taught you, abide in him. (ESV)
In the previous verse we looked at the false teachers. They were claiming to be the sole possessors of special knowledge. They were bringing harm to the church with their false teaching. They were deceivers. The church was left with wondering whether or not they needed special teachers to give them special knowledge. John reminds them that they already have the teacher they need.
Who is their teacher? John describes him as "the anointing that you have received." This is a description of the Holy Spirit. All believers have the Holy Spirit dwelling within them. This Spirit of God is the very same Spirit that inspired every word of Scripture in the Old and New Testaments. Consider that the very author of the Bible dwells within you If you want to be taught the truth you can look to the author of God's Word as your supreme instructor.
John tells us, "as [the Holy Spirit] has taught you, abide in him." How do we abide in him? We need to open the Word of God. As we read the Scriptures we have the Holy Spirit speaking to our hearts and teaching us the things that we need to know. As we spend time with him in prayer we learn more about him and begin to love him even more. His presence is available. If we abide in him, listen to him, guided by his words of Scripture, we will be guarded from the deceptions of the enemy.
Is the Holy Spirit, the anointing you have received, your teacher? Do you look to him to instruct you? No human teacher is greater than the Holy Spirit.