1 John 2:19
King James Version
“They went out from us, but they were not of us; for if they had been of us, they would have continued with us: but that they might be made manifest that they were not all of us.”
Context
16For all that in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world.
17And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever.
18Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time.
19They went out from us, but they were not of us; for if they had been of us, they would have continued with us: but that they might be made manifest that they were not all of us.
20But ye have an unction from the Holy One, and ye know all things.
21I have not written unto you because ye know not the truth, but because ye know it, and that no lie is of the truth.
22Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son.