Romans 14:23

But he who is uncertain [about eating a particular thing] is condemned if he eats, because he is not acting from faith. Whatever is not from faith is sin [whatever is done with doubt is sinful].

Romans 13:2

Therefore whoever resists [governmental] authority resists the ordinance of God. And those who have resisted it will bring judgment (civil penalty) on themselves.

1 Corinthians 8:7

However, not all [believers] have this knowledge. But some, being accustomed [throughout their lives] to [thinking of] the idol until now [as real and living], still eat food as if it were sacrificed to an idol; and because their conscience is weak, it is defiled (guilty, ashamed).

1 Corinthians 11:29-31

For anyone who eats and drinks [without solemn reverence and heartfelt gratitude for the sacrifice of Christ], eats and drinks a judgment on himself if he does not recognize the body [of Christ].

Romans 14:5

One person regards one day as better [or more important] than another, while another regards every day [the same as any other]. Let everyone be fully convinced (assured, satisfied) in his own mind.

Titus 1:15

To the pure, all things are pure; but to the corrupt and unbelieving, nothing is pure; both their mind and their conscience are corrupted.

Hebrews 11:6

But without faith it is impossible to [walk with God and] please Him, for whoever comes [near] to God must [necessarily] believe that God exists and that He rewards those who [earnestly and diligently] seek Him.

Treasury of Scripture Knowledge

Summary

And he that doubteth is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin.

Bible References

He that

1 Corinthians 8:7
However, not all [believers] have this knowledge. But some, being accustomed [throughout their lives] to [thinking of] the idol until now [as real and living], still eat food as if it were sacrificed to an idol; and because their conscience is weak, it is defiled (guilty, ashamed).

Damned

Romans 13:2
Therefore whoever resists [governmental] authority resists the ordinance of God. And those who have resisted it will bring judgment (civil penalty) on themselves.
1 Corinthians 11:29
For anyone who eats and drinks [without solemn reverence and heartfelt gratitude for the sacrifice of Christ], eats and drinks a judgment on himself if he does not recognize the body [of Christ].

Whatsoever

Titus 1:15
To the pure, all things are pure; but to the corrupt and unbelieving, nothing is pure; both their mind and their conscience are corrupted.
Hebrews 11:6
But without faith it is impossible to [walk with God and] please Him, for whoever comes [near] to God must [necessarily] believe that God exists and that He rewards those who [earnestly and diligently] seek Him.