Titus 1:15

To the pure everything is pure, but to the evil-minded and unbelieving nothing is pure, but their very minds and consciences are unclean.

Romans 14:20

You must not, just for the sake of food, undo the work of God. It is true, everything is clean, but it is wrong for a man to hurt the consciences of others by what he eats.

Romans 14:23

but the man who has misgivings about eating, and then eats, is thereby condemned, for he is not following his convictions, and anything that does not rest on conviction is wrong.

Romans 14:14

I know and as a follower of the Lord Jesus I am convinced that nothing is unclean in itself; a thing is unclean only to the man who regards it as unclean.

Matthew 15:18

But the things that come out of the mouth come from the heart, and they pollute a man.

Acts 10:15

The voice came to him again a second time, "Do not call what God has cleansed unclean."

Luke 11:39-41

But the Master said to him, "You Pharisees clean the outside of cups and dishes, but inside you are full of greed and wickedness.

1 Corinthians 6:12-13

I may do anything I please, but not everything I may do is good for me. I may do anything I please; but I am not going to let anything master me.

1 Corinthians 8:7

But it is not everyone that has this knowledge; for some, through being long accustomed to idols, still eat meat that has been sacrificed to them as really offered to an idol, and their consciences, being oversensitive, are troubled.

1 Corinthians 10:23

We are free to do anything, but not everything is good for us. We are free to do anything, but not everything builds up character.

1 Corinthians 10:25

Eat anything for sale in the meat market without raising any question, as far as conscience is concerned,

1 Corinthians 10:31

So whether you are eating or drinking or doing anything else, do it all to the honor of God.

1 Corinthians 11:27-29

Hence anyone who eats the bread or drinks from the Lord's cup in a way that is unworthy of it will be guilty of profaning the body and the blood of the Lord.

1 Timothy 4:3-4

who forbid people to marry and insist on abstinence from certain kinds of food that God created for men who believe and understand the truth to enjoy and give thanks for.

1 Timothy 6:5

and mutual irritation between people of depraved minds, who are lost to the truth and think of religion only as a means of gain.

Hebrews 9:14

how much more surely will the blood of the Christ, who with the eternal Spirit made himself an unblemished offering to God, purify our consciences from the old wrongdoing for the worship of the everliving God?

Hebrews 10:22

let us draw near to God in sincerity of heart and with perfect faith, with our hearts cleansed from the sense of sin, and our bodies washed with clean water.

Treasury of Scripture Knowledge

Summary

Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled.

General references

Bible References

The pure

Luke 11:39
But the Master said to him, "You Pharisees clean the outside of cups and dishes, but inside you are full of greed and wickedness.
Acts 10:15
The voice came to him again a second time, "Do not call what God has cleansed unclean."
Romans 14:14
I know and as a follower of the Lord Jesus I am convinced that nothing is unclean in itself; a thing is unclean only to the man who regards it as unclean.
1 Corinthians 6:12
I may do anything I please, but not everything I may do is good for me. I may do anything I please; but I am not going to let anything master me.
1 Corinthians 10:23
We are free to do anything, but not everything is good for us. We are free to do anything, but not everything builds up character.
1 Timothy 4:3
who forbid people to marry and insist on abstinence from certain kinds of food that God created for men who believe and understand the truth to enjoy and give thanks for.

Their

1 Corinthians 8:7
But it is not everyone that has this knowledge; for some, through being long accustomed to idols, still eat meat that has been sacrificed to them as really offered to an idol, and their consciences, being oversensitive, are troubled.
Hebrews 9:14
how much more surely will the blood of the Christ, who with the eternal Spirit made himself an unblemished offering to God, purify our consciences from the old wrongdoing for the worship of the everliving God?
Hebrews 10:22
let us draw near to God in sincerity of heart and with perfect faith, with our hearts cleansed from the sense of sin, and our bodies washed with clean water.

General references

Acts 24:16
Therefore I strive always to have a clear conscience before God and men.