Anything that is not of faith is Sin/Romans 14:23.

[WalterandDebbie]

And he that doubteth is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin. Romans 14:23.

Romans 14 King James Version (KJV)

1. Him that is weak in the faith receive ye, but not to doubtful disputations.

2 For one believeth that he may eat all things: another, who is weak, eateth herbs.

3 Let not him that eateth despise him that eateth not; and let not him which eateth not judge him that eateth: for God hath received him.

4 Who art thou that judgest another man's servant? to his own master he standeth or falleth. Yea, he shall be holden up: for God is able to make him stand.

5 One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind.

6 He that regardeth the day, regardeth it unto the Lord; and he that regardeth not the day, to the Lord he doth not regard it. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not, to the Lord he eateth not, and giveth God thanks.

7 For none of us liveth to himself, and no man dieth to himself.

8 For whether we live, we live unto the Lord; and whether we die, we die unto the Lord: whether we live therefore, or die, we are the Lord's.

9 For to this end Christ both died, and rose, and revived, that he might be Lord both of the dead and living.

10 But why dost thou judge thy brother? or why dost thou set at nought thy brother? for we shall all stand before the judgment seat of Christ.

11 For it is written, As I live, saith the Lord, every knee shall bow to me, and every tongue shall confess to God.

12 So then every one of us shall give account of himself to God.

13 Let us not therefore judge one another any more: but judge this rather, that no man put a stumblingblock or an occasion to fall in his brother's way.

14 I know, and am persuaded by the Lord Jesus, that there is nothing unclean of itself: but to him that esteemeth any thing to be unclean, to him it is unclean.

15 But if thy brother be grieved with thy meat, now walkest thou not charitably. Destroy not him with thy meat, for whom Christ died.

16 Let not then your good be evil spoken of:

17 For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost.

18 For he that in these things serveth Christ is acceptable to God, and approved of men.

19 Let us therefore follow after the things which make for peace, and things wherewith one may edify another.

20 For meat destroy not the work of God. All things indeed are pure; but it is evil for that man who eateth with offence.

21 It is good neither to eat flesh, nor to drink wine, nor any thing whereby thy brother stumbleth, or is offended, or is made weak.

22 Hast thou faith? have it to thyself before God. Happy is he that condemneth not himself in that thing which he alloweth.

23 And he that doubteth is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin.

 

[Dude-Dastic]

"for whatsoever is not of faith is sin." -- Romans 14:23

When I read that portion, I think of two things:

1. Whatever you do (assuming it's a good thing) that isn't done confidently is wrong. You should never go into something thinking it can't be done, that you can't do it, or that you'll fail. Be optimistic, not pessimistic.
2. Whatever you do that isn't according to the faith -- that is, one's system of religious beliefs and practices -- is wrong. All that you do should be based on your creed.

Of course, I could be wrong about this. :|

 

[Eugene]

Dear Brethren WalterandDebbie, I’ve always associated those verses of scripture having to do with missing the mark of, and being offensive in our purpose and walk. When we do something we don’t feel right about be it eating, or not eating we end up condemning ourselves, we can become reluctant to openly approach our Father who loves enough to have given us Jesus.
1 John 3:20 For if our heart condemn us, God is greater than our heart, and knoweth all things.
1 John 3:21 Beloved, if our heart condemn us not, then have we confidence toward God.
1 John 3:22 And whatsoever we ask, we receive of him, because we keep his commandments, and do those things that are pleasing in his sight.

Rom 8:32 He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?
Rom 8:33 Who shall lay any thing to the charge of God's elect? It is God that justifieth.
Rom 8:34 Who is he that condemneth (We can and do accuse ourselves)? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us.
Rom 8:35 Who shall separate us from the love of Christ?

 

[Jethro Bodine]

It's simple. If you aren't convinced that what you approve of doing is okay to do, then if you do that your doing is not of faith. This has nothing to do with faith in salvation. This is about faith in daily living.

It's easy to see that one can be relying totally and fully in faith on Christ for salvation, yet struggle with the day to day decisions about matters of faith in regard to what they should or should not be doing. Paul is simply saying that if you do something that you yourself consider wrong you condemn yourself because your doing is from not having the faith that it's okay to do. If you believe that it is sin to do something, but you do it anyway, obviously you are sinning in the eyes of God. You are not operating in the faith of knowing it's okay to do whatever it is that you are doing.