True and False workers
Mark 9:38 And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us.
Mark 9:39 But Jesus said, Forbid him not: for there is no man which shall do a miracle in my name, that can lightly speak evil of me.
Mark 9:40 For he that is not against us is on our part.
If the fruit is good and things are done in Jesus' name, they are for Jesus. They have good fruit.
Compare this to this verse:
Mat 7:15 Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves.
Mat 7:16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles?
Mat 7:17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.
Mat 7:18 A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit.
Mat 7:19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire.
Mat 7:20 Wherefore by their fruits ye shall know them.
Mat 7:21 Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven.
Mat 7:22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works?
Mat 7:23 And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.
Apparently these were false people claiming to do the work of God. Fake Christians with no eternal fruit, not of Jesus, deceivers and liars making merchandise of people seeking God. They had evil fruit and perhaps a false message.
And this verse:
Luke 13:23 Then said one unto him, Lord, are there few that be saved? And he said unto them,
Luke 13:24 Strive to enter in at the strait gate: for many, I say unto you, will seek to enter in, and shall not be able.
Luke 13:25 When once the master of the house is risen up, and hath shut to the door, and ye begin to stand without, and to knock at the door, saying, Lord, Lord, open unto us; and he shall answer and say unto you, I know you not whence ye are:
Luke 13:26 Then shall ye begin to say, We have eaten and drunk in thy presence, and thou hast taught in our streets.
Luke 13:27 But he shall say, I tell you, I know you not whence ye are; depart from me, all ye workers of iniquity.
Apparently these had only a casual knowledge of Jesus. They had not entered into the strait gate that is Jesus, into salvation. They acknowledged him with others, but not personally. One of many who claim to be Christian, but have no spiritual connection to him.