Romans 14:23

One person judges one day above another, another judges every day alike. Each person must be fully convinced in his own mind.

However, not all men have this knowledge; but some, being accustomed to the idol until now, eat food as if it were sacrificed to an idol; and their conscience, being weak, is defiled.

To the pure, all things are pure, but to those who are defiled and unbelieving, nothing is pure, but both their mind and their conscience are defiled.

But solid food is for the mature, who because of practice have their senses trained to discern both good and evil.