Romans 14:23

However, not every person knows this [truth]. For some people have been so used to an idol all this time that they still think of the idol [as a reality] when eating food that has been sacrificed to it. And their weak conscience becomes polluted. [Note: These people cannot seem to shake off the idea that somehow the idol is real, so feel guilty of wrongdoing when eating food sacrificed to it].

Therefore, the person who resists [these] authorities is opposing what God has ordained. And those who oppose [these authorities] will bring judgment on themselves.

For a person who eats and drinks without determining the significance of the body [of Jesus], [i.e., without showing proper reverence for Christ, as represented by the bread and cup (see verse 27), or without distinguishing this sacred memorial Supper from a common meal], eats and drinks judgment upon himself. [Note: Some apply "the body" in this verse to the church and explain it as a warning against failing to appreciate the unity that the Supper is intended to signify].

Everything is pure [i.e., ceremonially acceptable] to the person who is pure [i.e., who has been cleansed by the blood of Christ], but to those who are [spiritually] corrupt, and do not believe [in Christ], nothing is pure, but both their minds and consciences are corrupted. [Note: This statement was intended to remove the physical restrictions imposed by the law of Moses].

And unless one has faith, it is impossible for him to be pleasing to God, for the person who comes to God must believe that He exists and that He rewards those who seek Him.