1 John 3:10

10In this the children of God are manifest. He shortly draws this conclusion, that those in vain claim a place and a name among the children of God, who do not prove themselves to be such by a pious and holy life, since by this evidence they shew that they differ from the children of the devil. But he does not mean that they are thus manifested, so as to be openly recognized by the whole world; but his meaning is only this, that the fruit and adoption always appear in the life.