they went out from us… remained. See WCF 3.6; 17.2; WLC 61; BC 7. Having described the mark of obedience in 2:1-11, John describes the necessity of perseverance. Though once members of the community, they departed in order to oppose its teachings about the identity of Jesus. According to John, this demonstrated that they were not true members of the community. John goes on to explain how they denied that Jesus is the Christ (v. 22) and tried to lead others astray (v. 26).
An anointing from the Holy One - 1 John 2:20
an anointing from the Holy One. See WCF 1.5; WLC 4. The Father anointed the Son with the Holy Spirit at his baptism as the ultimate prophet like Moses, priest like Melchizadek, and king in David's line (see notes on Matt 3:16-17; Mk 1:9-11; Lk 3:21-22; Jn 1:32-34; Acts 10:38; Heb. 1:1-9). But, Christ also pours out his Spirit on his followers, giving them the task to imitate and represent him and to disciple the nations (see notes on Acts 1:8, 2:14-21). In this letter John describes these tasks as discernment and persevering witness (2:27-28). In his gospel, John describes the Spirit's work as convicting the world of its guilt with regard to sin and righteousness (see notes John 16:8-11). Those reading John's letter can be assured that their confession of Christ as the Just One, who died for sins is true and powerful.
Denies that Jesus is the Christ - 1 John 2:22
denies… Christ. In his gospel, John wrote to show that Jesus of Nazareth is the Messiah, the Son of God (see notes on John 20:31), because this claim was dividing the synagogue (see notes on John 9:22). In the wake of this division, some who were influenced by Greek dualism wanted to claim that Christ only seemed (dokeo¯) to be human. As God, he could not have assumed flesh and died an atoning death (see notes on 4:2-3, 15; 5:1, 6-8). Those who departed from John"s church embraced this early form of the Docetic heresy, denying the gospel
The Father - 1 John 2:23
the Father. See notes on Jn. 5:23; 14:6-7; 15:23
What you heard from the beginning - 1 John 2:24
what you heard from the beginning. John uses this phrase several times (1:1; 2:7, 13, 14; 3:8, 11, 2 Jn. 5-6) to describe his teaching, which gives eyewitness testimony to Jesus' historical ministry (see notes 1:1-3), a teaching that has formed and nourished their fellowship over the years
Eternal life - 1 John 2:25
eternal life. John points to God promise to undo what happened to Adam and Eve (see note on Gen. 3:22), which Jesus won because of his obedience (see note on Jn. 12:46) and experienced in his resurrection. Eternal life is identified with Jesus elsewhere (5:20), or it is found in him (5:11). This is the eternal life that was with God at the beginning (1:2), and those who are in the Son experience it from the first moment of faith into eternity as a gift from God (5:12-13). Indeed, John says believers have already passed from death to life (see notes on Jn. 5:24-29)
You do not need anyone to teach you - 1 John 2:27
to teach you. See WCF 1.5; 17.2; WLC 4, 79; HC 32. The Holy Spirit enlivens the minds of believers and helps them understand God's word. The Spirit also gives discernment. This does not mean Christians do not need teaching, however. Because all believers have the indwelling Spirit and its gifts, they should listen to each other, but test what they here by what the Spirit says through the Scriptures. Those who departed may have claimed special knowledge or insight from the Spirit, but John reminds his readers they have the same Spirit who has given them true knowledge and understanding about Jesus.