Romans 14:21-23 It is good neither to eat flesh, nor to drink wine, nor any thing whereby thy brother stumbles, or is offended, or is made weak. Has thou faith? have it to thyself before God. Happy is he that condemns not himself in that thing which he allows. And he that doubts is damned if he eat, because he eats not of faith: for whatsoever is not of faith is sin. 

‘It is good neither to eat flesh, nor to drink wine, nor any thing whereby thy brother stumbles, or is offended, or is made weak.’ It is better to deny self to personal pleasures than to cause brethren to apostatize (Matt. 18:6-10; 1Cor. 8:7-13; 10:23-31).

‘Eat flesh’ meat is permitted to be eaten and we cannot tell others to not eat meat and only vegetables (14:2, 14-17; Col. 2:14-17; 1Tim. 4:1-6).

‘Wine’ the word “wine” is used for all kinds of drinks – even the grape juice when it is still in the cluster (Isa. 65:8). Hence, it does not always refer to intoxicating drinks. They should be left alone in view of the law against drinking alcohol (1Cor. 6:9-11; Gal. 5:19-21; etc.).

‘Nor any thing whereby thy brother stumbles’ – not only doubtful things that are mentioned, but anything not listed which causes another to apostatize and be lost must be laid aside.

‘Stumbles’ [Greek: proskopto] to strike the foot against; to err from the truth (Jas. 5:19-20). Beat upon (until the thing is destroyed, Matt. 7:27); dash against (Matt. 4:6; Luke 4:11); stumble (John 11:9-10; Rom. 9:32; 14:21; 1Pet. 2:8).

‘Offended’ [Greek: skandalizo] to offend. It is used generally in the New Testament of total apostasy from Christ (Matt. 5:29-30; 11:6; 13:21, 57; 15:12; 17:27; 18:6-9; 24:10; 26:31-33; Mark 4:17; 6:3; 9:42-47; 14:27-29; Luke 7:23; 17:2; John 6:61; 16:1; Rom. 14:21; 1Cor. 8:13; 2Cor. 11:29).

‘Weak’ [Greek: astheneo] strengthless; without power to distinguish sufficiently between right and wrong, good and evil, or lawful and unlawful.

‘Has thou faith?’ The last question in Romans. The word faith here means the full persuasion that one is right, lawful, and sanctioned by God in this act.

‘Happy is he that condemns not himself in that thing which he allows.’ Do not condemn yourself over anything not specifically forbidden in Scripture by plain command. Do not permit your conscience to be swayed by wrong religious background or constant religious turmoil over doubtful things.

‘For whatsoever is not of faith is sin.’ Anything done to violate the faith principle by which one is saved, and by which he lives (1:17; Heb. 10:38), is sin. One must know beyond all doubt or hesitation in his mind that what he allows is in perfect accord with the Word of God before he acts.