What does 1 John 2:12 mean?

Verse 12 is the first of six poetic phrases which each begin by naming a target audience. The first half of the poem is three sentences introduced with the phrase, "I am writing to you." The second half is an additional three sentences, each beginning with the phrase, "I write to you." Each audience is mentioned in the first and second halves of the poem.

The first one is addressed to "little children," and mentions forgiveness of sins. These "little children" are not implying literal toddlers. More likely, this means young believers. These are newer Christians whose sins have been forgiven, and are one of the groups this letter is targeted at. John clearly knew some of the believers in the congregation (or congregations) reading his letter had only recently come to faith in Christ.

Verse 13, in the second half of this poem, will address this specific audience a second time. Verse 13 notes that these "children" know the Father. This brings to mind Christ's teaching in John 14:6, that He is "the way, and the truth, and the life. No one comes to the Father except through me." Those who know the Father are those who have come to faith in Christ and whose sins have been forgiven.