According to James 4:17, it really is a case of “if you have to ask honey…” then it probably is. If we feel unsettled about our actions and pray about it and can’t get peace; if we do something that we’re constantly thinking about and wondering if it’s sinful even after seeking answers from whatever sources; then for us, it may be a sin. For example, some people may say it’s okay to tell white lies to protect another person’s feelings, we may even rationalize it in our own minds that it’s innocent and for the good of another. But if in our hearts, WE know it’s not right, then no one, not Google, nor our minister, will be able to give us peace in that regard; we’ll constantly be questioning and seeking and searching
Some sins it’s easy to categorize universally and say yes it’s a sin but others it will be for each individual to know in their heart whether it is or it isn’t. If we take the example of sexual sin for example, the bible has clearly labelled certain things as sexual immorality and therefore wrong but what about other grey areas that it doesn’t mention quite as precisely such as masturbation, for example, or doing everything but full-on sex with a non-married partner. There are no clear “thou shalt nots” with these issues. One may search online or in literature or seek spiritual guidance from an elder in the Lord (pastor, minister, prayer partner etc) and get different answers that do not satisfy the soul.
What I think counts ultimately, if you’re engaged in something that you feel deep down isn’t right and bothers you, then it is unnecessary for you to continue to debate it and feel unsettled about it. Let’s not try to play smart and be just Christian enough to pass within “the boundaries” of not sinning. The Holy Spirit within us convicts us so that we, for the most part, can tell right from wrong. We should be living abundant, joyful lives in the open, not shady lives where we’re always straddling the barriers of what is and isn’t sin.
Maybe truly, the behavior in question isn’t sinful, but if we feel like it may be, then we need to examine whether the Spirit is guiding us away from a path that might consume us and lead us to actual sin. Maybe making out with a committed (non-married) partner isn’t a sin, but maybe one may feel unsettled about it and question it’s sinful nature because they know it could lead them down the path to sexual sin etc.
If knowingly, we do what feels wrong to us, no matter the perspective of the world as to how innocuous it is, then for us, it’s a sin. This verse gives us the simple answer, if YOU do what YOU know is not right or just as bad if you DON’T do what you KNOW is right, then it’s a sin.