“In this the children of God and the children of the devil are manifest: Whoever does not practice righteousness is not of God, nor is he who does not love his brother.”
Whoever does not practice righteousness is not of God,
“Whoever” here refers to the non-Christian. The Greek phrase “of God” means that a person without divine righteousness does not find his source in God. His source for righteousness is in his sin capacity. He finds his source is in the relative righteousness of man. We can never trace sin to God because God is absolute.
Righteousness involves right relationship with God. Fellowship with God rests on what is right with God. Children of God bear characteristic marks that stamp their true nature. Anyone who does not manifest standards of righteousness does not reveal his true nature. A believer in fellowship produces the very character of Christ.
nor is he who does not love his brother
The “he” here is the believer out of fellowship who manifests characteristics like the non-Christian. He hates and despises his fellow believer. This is a manifestation of an unbeliever.
Righteousness is too vague so John specifies what he means by righteousness – loving a brother. Love is the appropriate manifestation of the divine nature. The absence of manifestation of righteousness indicates a person not walking with God in fellowship. A loveless believer cannot commune with God who in His very essence is love.
Not loving our brother is a specific case of not manifesting divine righteousness. Absence of love for fellow Christians is an indication of absence of fellowship with God. An important manifestation of fellowship with God is love of fellow Christians.
Ga 5: 14 “For all the law is fulfilled in one word, even in this: ‘You shall love your neighbor as yourself.” 15 But if you bite and devour one another, beware lest you be consumed by one another!’”
We can distinguish between a Christian and a non-Christian by whether they have genuine fellowship with God or not.
There is a method for determining whether we operate out of our sin capacity or out of our divine capacity. The inner nature of the divine “seed” (3:9) will manifest itself in “righteousness” and “love.” The essence of righteousness [fellowship with God] manifests itself in love. Love is the distinct badge of being a believer. This is what decisively distinguishes between a believer and an unbeliever.
Jn 13: 34 “A new commandment I give to you, that you love one another; as I have loved you, that you also love one another. 35 “By this all will know that you are My disciples, if you have love for one another.”
This means that you love Christians who love you and you love Christians who do not love you. You love the Christians who are nice and easy to get along with. You love those who communicate with you and you love those who do not communication with you.
If we love fellow Christians, we take care how we treat them. If someone says that he loves his fellow Christian at church but steals from him at work, he does not love his brother. There is a correspondence between what we say about love and what we do with love.
2: 9 “He who says he is in the light, and hates his brother, is in darkness [out of fellowship with God] until now.”
We know people who walk with God by their righteous fellowship with God and their love for fellow Christians. Only God can give us true righteousness and love. He fills the container called the believer with the dynamics of who He is.
Sin does not appeal to the Christian in fellowship like it once did. He now has a burr in his saddle when he sins. He does not want to grieve the Holy Spirit (Ep 4:30). Peace leaves his soul when he steps out of fellowship with God. He cannot leave it unresolved. He confesses his sin immediately (1:9).
The non-Christian has no capacity to do the righteousness of God because he does not possess a divine nature or capacity. He may do good in a relative sense according to how men measure goodness. A genuine believer can do righteousness acceptable to God’s standard of righteousness. He acts according to God’s righteousness imputed to him. This is a God-produced righteousness, not a man-made righteousness. After God imputes His righteousness to the believer, He can then move through that new nature to produce His righteousness according to His norms.
The love of God will produce love through the child of God when the child of God walks in fellowship with the Son of God. Man without God is essentially selfish. Unselfish love manifests God’s self-sacrificing love. Unselfish love proves that a believer is in fellowship with God.