3 John 1:11 Beloved, follow not that which is evil, but that which is good. He that doeth good is of God: but he that doeth evil hath not seen God.
12 Demetrius hath good report of all men, and of the truth itself: yea, and we also bear record; and ye know that our record is true.
John tells us in theses verses two different things. First he refers to the people who do not follow what is good but continues in pursuing those things which are evil which means they are not true followers of God. He goes on to say the ones who do good and helps their brethren is of God and those that continue to do evil have never really known God. Last he tells us that for those that we know who do good we should testify of their good deeds to others and encourage all that know the truth of God’s word to let people know of those that are true followers of God. We should also be aware of those false teachers and warn people of them.