Titus 1:15

All is pure to those who are pure. But to those who are corrupt and unbelieving, nothing is pure, but both their minds and consciences are corrupted.

Romans 14:20

Do not destroy the work of God for the sake of food. For although all things are clean, it is wrong to cause anyone to stumble by what you eat.

Romans 14:23

But the man who doubts is condemned if he eats, because he does not do so from faith, and whatever is not from faith is sin.

Romans 14:14

I know and am convinced in the Lord Jesus that there is nothing unclean in itself; still, it is unclean to the one who considers it unclean.

Matthew 15:18

But the things that come out of the mouth come from the heart, and these things defile a person.

Acts 10:15

The voice spoke to him again, a second time, "What God has made clean, you must not consider ritually unclean!"

Proverbs 21:4

Haughty eyes and a proud heart -- the agricultural product of the wicked is sin.

Haggai 2:13

Then Haggai asked, "If a person who is ritually unclean because of touching a dead body comes in contact with one of these items, will it become unclean?" The priests answered, "It will be unclean."

Zechariah 7:5-6

"Speak to all the people and priests of the land as follows: 'When you fasted and lamented in the fifth and seventh months through all these seventy years, did you truly fast for me -- for me, indeed?

Luke 11:39-41

But the Lord said to him, "Now you Pharisees clean the outside of the cup and the plate, but inside you are full of greed and wickedness.

1 Corinthians 6:12-13

"All things are lawful for me" -- but not everything is beneficial. "All things are lawful for me" -- but I will not be controlled by anything.

1 Corinthians 8:7

But this knowledge is not shared by all. And some, by being accustomed to idols in former times, eat this food as an idol sacrifice, and their conscience, because it is weak, is defiled.

1 Corinthians 10:23

"Everything is lawful," but not everything is beneficial. "Everything is lawful," but not everything builds others up.

1 Corinthians 10:25

Eat anything that is sold in the marketplace without questions of conscience,

1 Corinthians 10:31

So whether you eat or drink, or whatever you do, do everything for the glory of God.

1 Corinthians 11:27-29

For this reason, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of the body and blood of the Lord.

1 Timothy 4:3-4

They will prohibit marriage and require abstinence from foods that God created to be received with thanksgiving by those who believe and know the truth.

1 Timothy 6:5

and constant bickering by people corrupted in their minds and deprived of the truth, who suppose that godliness is a way of making a profit.

Hebrews 9:14

how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our consciences from dead works to worship the living God.

Hebrews 10:22

let us draw near with a sincere heart in the assurance that faith brings, because we have had our hearts sprinkled clean from an evil conscience and our bodies washed in pure 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.

Bible References

The pure

Luke 11:39
But the Lord said to him, "Now you Pharisees clean the outside of the cup and the plate, but inside you are full of greed and wickedness.
Acts 10:15
The voice spoke to him again, a second time, "What God has made clean, you must not consider ritually unclean!"
Romans 14:14
I know and am convinced in the Lord Jesus that there is nothing unclean in itself; still, it is unclean to the one who considers it unclean.
1 Corinthians 6:12
"All things are lawful for me" -- but not everything is beneficial. "All things are lawful for me" -- but I will not be controlled by anything.
1 Corinthians 10:23
"Everything is lawful," but not everything is beneficial. "Everything is lawful," but not everything builds others up.
1 Timothy 4:3
They will prohibit marriage and require abstinence from foods that God created to be received with thanksgiving by those who believe and know the truth.

Their

1 Corinthians 8:7
But this knowledge is not shared by all. And some, by being accustomed to idols in former times, eat this food as an idol sacrifice, and their conscience, because it is weak, is defiled.
Hebrews 9:14
how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our consciences from dead works to worship the living God.
Hebrews 10:22
let us draw near with a sincere heart in the assurance that faith brings, because we have had our hearts sprinkled clean from an evil conscience and our bodies washed in pure water.

General references

Leviticus 7:19
The meat which touches anything ceremonially unclean must not be eaten; it must be burned up in the fire. As for ceremonially clean meat, everyone who is ceremonially clean may eat the meat.
Leviticus 10:10
as well as to distinguish between the holy and the common, and between the unclean and the clean,
Leviticus 11:34
Any food that may be eaten which becomes soaked with water will become unclean. Anything drinkable in any such vessel will become unclean.
Deuteronomy 14:3
You must not eat any forbidden thing.
Acts 24:16
This is the reason I do my best to always have a clear conscience toward God and toward people.

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