My dearly loved ones, I am not writing to you about a new commandment, but about an old one. [It is the one] you had learned about from the beginning. [Note: This is the commandment to love one another (3:1: II John 5) which Jesus had taught his disciples during His earthly ministry. See Mark 12:31]. This old commandment is the word [of God] which you heard [previously].

I am writing to you fathers, because you have known Him [i.e., Christ], [who has existed] from the beginning [See John 1:1]. I am writing to you young men, because you have overcome the [power of the] evil one [i.e., through faith they had gained victory over Satan, See 5:4].

These antichrists left our group [i.e., withdrew their fellowship from us], but they were not [really a part] of us, for if they had been, they would have continued [to participate] with us. But, by their leaving us, it proved that none of them were [really] a part of our group [after all].

not [hate each other] the way Cain did, who belonged to the evil one [i.e., Satan], when he murdered his brother [Abel]. And why did he murder him? It was because his [own] actions were evil and his brother's were righteous [See Heb. 11:4].

So, do not be surprised, brothers, if the people of the world hate you.