1 John 1:6

If we say that we have fellowship with Him, and are walking in the darkness, we lie, and do not the truth;

1 John 4:20

If anyone says, "I love God," and hates his brother, he is a liar; for he that loves not his brother whom he has seen, cannot love God Whom he has not seen.

1 John 1:10

If we say, "We have not sinned," we make Him a liar, and His word is not in us.

John 3:19-21

And this is the judgment, that the Light hath come into the world, and men loved the darkness rather than the Light; for their works were evil.

John 12:35

Jesus, therefore, said to them, "Yet a little while is the Light among you. Walk while ye have the Light, lest darkness overtake you; and he that walks in the darkness knows not where he is going.

1 John 2:4

He who says, "I have known Him," and does not keep His commandments, is a liar, and the truth is not in him;

Revelation 3:17-18

Because you say, 'I am rich, and have gotten riches, and have need of nothing'; and do not know that you are the wretched one, and pitiable, and poor, and blind, and naked!

Matthew 7:22

Many will say to Me in that day, 'Lord, Lord, did we not prophesy by Thy name? and by Thy name cast out demons, and by Thy name do many mighty works,'"

John 8:12

Again, therefore, Jesus spake to them, saying, "I am the Light of the world: he that follows Me shall not walk in the darkness, but shall have the Light of life."

John 8:44-45

Ye are of your father the Devil; and the desires of your father ye wish to do. He was a murderer from the beginning, and has not stood in the truth, because there is no truth in him. When he speaks a lie, he speaks of his own; because he is a liar, and the father of it.

John 11:10

but, if any one walks in the night, he stumbles, because the light is not in him."

John 12:46

I have come a light into the world, that every one who believes on Me may not abide in the darkness.

2 Corinthians 6:14-16

Become not unequally yoked with unbelievers; for what fellowship have righteousness and lawlessness? And what communion has light with darkness?

1 Timothy 4:2

in hypocrisy of men speaking lies, branded in their own conscience with a hot iron;

James 2:14

What profit is it, my brethren, if anyone says he has faith, but has not works; can such faith save him?

James 2:16

and one of you say to them, "Go in peace, be warmed and filled," but ye give them not the things needful for the body, what does it profit?

James 2:18

But some one will say, "You have faith, and I have works": show me your faith apart from your works, and I will show you my faith by my works.

1 John 1:3

that which we have seen and heard we declare to you also, that ye also may have fellow-ship with us; and our fellowship also is with the Father, and with His Son Jesus Christ.

1 John 1:8

If we say, "We have no sin," we deceive ourselves, and the truth is not in us.

1 John 2:9-11

He who says that he is in the light, and hates his brother, is in the darkness even until now.

Treasury of Scripture Knowledge

Summary

If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth:

Do not

Bible References

If

1 John 1:8
If we say, "We have no sin," we deceive ourselves, and the truth is not in us.
1 John 2:4
He who says, "I have known Him," and does not keep His commandments, is a liar, and the truth is not in him;
1 John 4:20
If anyone says, "I love God," and hates his brother, he is a liar; for he that loves not his brother whom he has seen, cannot love God Whom he has not seen.
Matthew 7:22
Many will say to Me in that day, 'Lord, Lord, did we not prophesy by Thy name? and by Thy name cast out demons, and by Thy name do many mighty works,'"
James 2:14
What profit is it, my brethren, if anyone says he has faith, but has not works; can such faith save him?
Revelation 3:17
Because you say, 'I am rich, and have gotten riches, and have need of nothing'; and do not know that you are the wretched one, and pitiable, and poor, and blind, and naked!

Fellowship

1 John 1:3
that which we have seen and heard we declare to you also, that ye also may have fellow-ship with us; and our fellowship also is with the Father, and with His Son Jesus Christ.
2 Corinthians 6:14
Become not unequally yoked with unbelievers; for what fellowship have righteousness and lawlessness? And what communion has light with darkness?

We lie

1 John 1:10
If we say, "We have not sinned," we make Him a liar, and His word is not in us.
1 John 4:20
If anyone says, "I love God," and hates his brother, he is a liar; for he that loves not his brother whom he has seen, cannot love God Whom he has not seen.
John 8:44
Ye are of your father the Devil; and the desires of your father ye wish to do. He was a murderer from the beginning, and has not stood in the truth, because there is no truth in him. When he speaks a lie, he speaks of his own; because he is a liar, and the father of it.
1 Timothy 4:2
in hypocrisy of men speaking lies, branded in their own conscience with a hot iron;

Do not

John 3:21
but he that does the truth comes to the Light, that his works may be made manifest, that they have been wrought in God."