New Defender's Study Bible Notes
14:23 damned. This does not mean eternal damnation, but only “condemnation,” or “judgment.” Both God and the believer himself (Romans 14:22) condemn this doubtful act if he does it against his own conscientious scruples, even if a supposedly more mature believer assures him it is all right.
14:23 not of faith. Although all things are, indeed, legal for a true Christian, he will try to do only those things which please his Lord. When he encounters questions not specifically mentioned in Scripture (e.g., smoking, movies), he should consider the various Scriptural principles that are given as guideposts to help him make such decisions. One of those is given in this verse, namely, he should be able to do it in full confidence that it is pleasing to Christ. Some of the principles, with typical supporting Scriptures, may be noted as follows:
(1) The act has positive value and is, without question pleasing to the Lord (Romans 14:23; I Corinthians 10:23; Colossians 4:5);
(2) The act is consistent with our new life in Christ (Colossians 3:1-4; II Timothy 2:4; II Corinthians 5:14-15);
(3) We can sense the positive leading of the indwelling Holy Spirit (I Corinthians 6:19-20; Galatians 5:16-18);
(4) The act will not diminish our Christian influence (Romans 14:13,21; I Corinthians 8:8-13; I Thessalonians 5:22);
(5) The act does not pose a danger of our becoming addicted to it (I Corinthians 6:12; Ephesians 5:18; James 1:14-15);
(6) It can be done consistently with the example set by Jesus (I Peter 2:21; I John 2:6; Philippians 2:5);
(7) It can be done in confidence that it brings glory to God (I Corinthians 10:31; Colossians 3:23).
This is certainly not an exhaustive list of relevant principles or appropriate Scriptures, but is at least indicative of what to look for.