In contrast to antichrists who deny essential truths about Jesus Christ (1 John 2:18–19; cf.2:22; 4:3; 2 John 7), the readers of 1 John are told, “But you have been anointed by the Holy One, and you all have knowledge” (1 John 2:20), literally translated, “But you have an anointing from the Holy One, and you all know.”
That the anointing is from the Holy One is that it is from Jesus Christ. John later states that “the anointing” was something his readers “received from him” (1 John 2:27), the same “him” who whose “coming” is mentioned in 1 John 2:28 (“his coming”), indicating the “him” in 2:27 is Jesus, the One who is coming again (cf. Rev 22:7). Jesus is called the Holy One in other texts as well (Mark 1:24; Luke 4:34; John 6:69; Acts 2:27; 3:14; Rev 3:7).
The anointing itself is something that “abides in you” and “teaches you about everything” (1 John 2:27). Paul elsewhere states that “God…has anointed us,” which is to say that He “has also put his seal on us and given us his Spirit in our hearts as a guarantee” (2 Cor 1:21–22). Paul’s focus is on God’s giving of the Spirit as a seal and guarantee of redemption (cf. Eph 1:13–14; 4:30). John’s focus is Jesus’ giving of the Spirit to an individual to teach him about the gospel in a way that involves the individual’s acceptance of it. (It could be said that either God or Christ anoints―the Father and the Son give the Spirit together. Cf. John 14:26; 15:16.)
What John teaches in 1 John 2:20, 27 about accepting truth is taught by Paul in 1 Cor 2:14–15. Speaking of an unbeliever’s rejection of God’s revealed truth, Paul states, “The natural person does not accept the things of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned” (1 Cor 2:14). In contrast, the believer does accept God’s truth: “The spiritual person judges all things” (1 Cor 2:15). The unbeliever does not have the Spirit and rejects truth, and the believer does have the Spirit and accepts truth (cf. 1 Cor 2:12–13).
The Spirit’s anointing is not something that imparts truth. The unbelievers in 1 John 2:19 had to have known the objective content of the gospel as did John’s readers; they were once among the readers and eventually left the church (1 John 2:19). Rather, anointing is the Spirit’s work in someone that enables the individual to savingly accept the truth that he already knows. Theologically, this anointing necessarily comes at the point of one’s conversion.
Summarizing the above, every believer is anointed with the Spirit at conversion. This anointing entails the Spirit’s abiding presence, ensuring the believer of his future redemption. As it did first at his conversion, this anointing also helps him to continually learn, understand, and accept the truth of God.