βWhat does Paul mean when he says that whatsoever is not of faith is sinβ?
βAnd he that doubteth is damned if he eat, because he eateth notΒ of faith: for whatsoever is not of faith is sinβ (Rom. 14:23).
We know that faith comes by hearing the Word of God (Rom.Β 10:17). The Word of GodΒ through PaulΒ says that we can eat all thingsΒ (1 Tim. 4:4), but he who is βweak in faithβ (Rom. 14:1) doubts this andΒ limits himself to eating βherbsβ (Rom. 14:2). His faith has not yet maturedΒ to believe Paul when he says he can eat meat, so βhe that doubtethβ¦Β if he eatβ¦he eateth not of faith.β
But if he wouldnβt eat it βof faith,β why would he eat it? Well, inΒ this passage, he might eat meat trying to follow the example of hisΒ stronger brother. This is why Paul encourages strong brethren not toΒ eat meat in front of a weaker brother (Rom. 14:15), which might make βtheΒ conscience of him which is weak be emboldened to eatβ meat (cf.Β 1 Cor. 8:10). If he eats meat to try to walk in the footsteps of his strongerΒ brother, rather than eating it because βof faithβ in Godβs Word, itΒ will cause him to stumble (Rom. 14:13,21) by doing something thatΒ bothers his conscience.
Back to our question. How come βwhatsoever is not of faith isΒ sinβ? It is because βto him that esteemeth any thing to be unclean, toΒ him itΒ isΒ uncleanβ (Rom. 14:14). God actually adjusts the definition of whatΒ is unclean to agree with a weak brotherβs conscience. Since his faithΒ does not yet believe that he can eat meat, βhe eateth not of faith,β andΒ whatsoever is not of faith is sinΒ to him.
Why would a weak brother βbe damned if he eatβ? Well, the wordΒ βdamnationβ doesnβt always refer toΒ eternalΒ damnationΒ in Hell. IfΒ all damnation was eternal, the Lord was being redundant in speakingΒ of βeternal damnationβ (Mark 3:29). Likewise, if all damnation wasΒ to Hell, He would not have had to add the words βof Hellβ when HeΒ spoke of βthe damnation of Hellβ (Matt. 23:33). The word βdamnationβΒ simply meansΒ condemnationΒ orΒ judgmentΒ of any kind. ThoseΒ who resist the government βshall receive to themselves damnationβ (Rom. 13:1,2), the judgment and condemnationΒ of the government.Β So when a weak brother eats meat that he believes is unclean, it is sinΒ for him, and he is condemnedΒ by his own conscience, since he judgesΒ what he has done to be sinful. source