You have an anointing from the Holy One, and you know the truth.
Now consider verse 27 to find out what abides in these Christians: "But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him." It is the "anointing" that abides in these Christians that enables them to know. The message of verse 24 is the anointing of verse 27. As Barclay says, "Verses 24 and 27 are almost exactly parallel in expression...That which you have received from the beginning and the anointing are exactly parallel" (83). The word of God, which they had heard, is the "unction from the holy One." (4) The anointing so instructs these Christians that "ye need not that any man teach you." This teaching accords with Hebrews 8:11 where the writer declares that we who live under the new covenant have no need for someone to say, "Know the Lord: for all shall know me, from the least to the greatest." Why? Because God said, "I will put my laws into their mind, and write them in their hearts." This knowledge comes from the "anointment," the word of God. (5) Further, John says, "the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you...." The anointing cannot refer to the Holy Spirit as the teacher, for He (John 16:13) is not an it. (Compare 2 Timothy 3:17.)