The goal is “not sinning” (2:1a). In another purpose statement, John says one of the goals of the writing of this letter is that the reader will not sin. Even though we cannot “not sin,” and to claim we to “not sin” is a lie (and is therefore a sin).
But we will sin, so Jesus is our Advocate (2:1b). The world John uses here (παράκλητος) is the same used in John 14:16 to refer to the Holy Spirit. The verb can have the sense of pleading a case, as in 2 Corinthians 5:20, Paul implores his readers to be reconciled with God. The word is sometimes translated as “comforter,” someone who encourages or comforts someone in a difficult situation.
Although many preachers imagine this word to refer to Jesus functioning as a legal advocate, the use of this word for lawyer or attorney is rare (BDAG, although NIDNTEE 2:539 says it is “a personal term with legal connotations”). In Roman legal settings, a person could hire a person to speak for them, perhaps a patronus, a patron could speak on behalf of their client accused of some crime. (Some readers may hear the allusion to this practice in the Harry Potter stories, summoning a helper in the time of need, expecto patronum!)
It may be that John has in mind the Jewish view that angelic beings stand before God as advocates. Like Archangel Michael in Second Temple Judaism, Jesus stands before the throne of God advocating on our behalf.
What does the word propitiation mean? The word the ESV translates as “propitiation” is another allusion to the Old Testament. The NIV and NRSV translates ἱλασμός as “atoning sacrifice,” which better communicates to modern readers what this word means.The word has the sense of “appeasement necessitated by sin, expiation” (BDAG). A god has been offended, so the offender must sacrifice in the right way to turn aside the god’s wrath. In the Law, the word is used for a sacrifice of restitution, Numbers 5:8.
In the Greco-Roman world, a god might be calmed by human or animal sacrifice, but other rites of purification or prayers were also common. Less familiar to modern readers, sometimes ritual dances and games dedicated to the god turned aside wrath (F. Büchsel, TDNT 3:311-12).
In the Old Testament the word and its cognates almost always refer to appeasing the wrath of God (Lev 1:4, for example; see NIDNTEE “ἱλάσκομαι,” 2:531.).
John finishes the first section of this letter with a clear declaration God has in fact forgiven our sin, but sin remains a serious problem for the believer. We can have confidence in the faithfulness of God to forgive our sin and complete reliance on Jesus as our atoning sacrifice and advocate. But there is a need to take seriously the effect of sin on the life of the believer and on the community of believers.