1 John 3:10

In this the children of God are manifest
By regenerating grace, and not sinning, in the sense before explained, in consequence of it: adoption is an act of God's grace and sovereign will; it is secret in his own heart, and is secured in divine predestination, and in the covenant of grace, and is antecedent to regeneration: regeneration and faith do not make men the children of God, but manifest them to be so; adoption makes them the children of God, and entitles them to the inheritance; regeneration gives them the nature of the children of God, and makes them meet for it, and manifests their right unto it; not to the men of the world, but to themselves and other saints:

and the children of the devil;
such as imitate him, do his will and his lusts, and are openly under his power and influence; these are distinguishable from regenerate persons, and the children of God, by their lives and conversations; so the people of the nations of the world are called, (ywnb) , "the children of Samael", and the serpent, by the Jews ^F13, which are with them the names of the devil.

Whosoever doth not righteousness is not of God:
that is, he does; not appear to be born of God, who does not by faith lay hold on the righteousness of Christ for his justification before God, and acceptance with him; and who does not do works of righteousness in faith from a principle of love, and with a view to the glory of God; for where regenerating grace is, there will be such graces and such practices:

neither he that loveth not his brother;
for as he that loveth God, and Christ, and the brethren, appears manifestly to be born again, and to have passed from death to life, so he that does not is in darkness, in a state of unregeneracy, and walks and continues therein; for was he born again, he would be taught of God to love the saints; see ( 1 John 4:7 ) ( 3:14 ) ( 2:11 ) .