People tend to identify with other people who like to do what they do. Especially as it pertains to sinful behaviors. So they associate with other people who have like minded sinful desires and they use groupthink to justify what they do. This can happen in a bar or a church or even the club. What do you make of this theory?
Well, if everyone is doing it, it doesn't make the person feel so bad, even though they may know it is wrong.
However, I think people in general like to be around people like themselves. People who like baseball like to hang with other people that share the same interest. That doesn't make baseball sinful.
One could misuse the bible, misquote it, and claim that sinful "pork eaters" like to sin by eating at rib places together.
The real tragedy in such situations is that the real "sinners" are those that band together, denying their own sin, and point and another, and condemn them as an "unrepentant sinner." The enjoy feeling superior and self righteous, and in doing so, basically spit on the crucifiction, thinking themselves worthy and deserving of salvation, rather than acknowledging their own sin, and being forgiving of others, and needing Christ.
My theory about sin is this: Christianity has never ever been about sin. It has never been a book of laws you should not commit. Rather, as Christ explained, we are simply to love our neighbor as ourselves, and in doing so, show our love to God. When we love each other, we don't need to worry about sinning against others, because in love, we offer instead love, help, give with generosity not asking in return, and are happy for another's fortune rather than selfishly envy it.
Put simply, we are called to love, and when we do, we know God and are born of God. (1 John 4:7-8). It's that simple. And if we do not love, or do not focus on love, we have completely missed the point.