A common misinterpretation views this as introducing an entirely novel commandment unrelated to the old one of loving others, perhaps as a separate moral code or ritual, ignoring its direct connection to the love command in the prior verse and its renewal through Christ's example; others mistakenly take 'darkness is past' as an absolute eradication of all evil immediately upon belief, rather than a progressive reality in the believer's life amid ongoing spiritual growth.
I John 2:8
King James Version (1769)
8 Again, a new commandment I write unto you, which thing is true in him and in you: because the darkness is past, and the true light now shineth.
John reaffirms the commandment to love one another as new because it finds its perfect expression and fulfillment in Christ, who lived it out fully, and it becomes reality in believers as they walk in His light, with the darkness of sin and hatred progressively giving way to the shining of the true light of truth and love.