I think the word "holy" has acquired some implications that are adding to its confusion. Although holiness involves an avoidance of sin it is not about avoiding sin.
In my studio I have a particular computer reserved only for editing audio and video. I never play games on it, never browse the web on it. The only software installed on it is the operating system and the various programs I have that assist me in capturing and editing audio and video. It is a fully capable computer well able to do anything a modern computer can do. I could easily use that computer for other things but in order to keep it functioning well for its purposes I do not use it for anything that could harm its ability to perform its dedicated purpose.
We too are are likewise set aside to be a manifestation of the redemptive love of God in the contexts of our relationships and responsibilities. We are to be in the world fully engaged with it but with a constant difference: we are the body of Christ that brings His presence into each and every context. It is wise for us to avoid entangling ourselves in attitudes or choices that compromise that manifestation. But that is merely an observable absence, our focus is proactively being the love of God.
Some would like it to be about sin management. I don't really know why but to be honest I cannot help wonder if it is because they are so distracted by temptations that they think this will help them stop doing things they know are inappropriate. And no doubt to a certain extent it works, but only by choking off the love. Love on its mission passes by the temptations often unaware of them because its busy with other things.
Some would like to make it all about what we believe and where we stand on the issues. I do not really know this either but can't help but wonder if such people are unwittingly trying to gain heavenly daddy's approval by adopting a system of thinking they imagine impresses God. Now to be sure, we cannot function in the world by faith without coming to certain points of view. It helps us get organized and be oriented. But love on its mission is more concerned with touching others redemptively than on the details that made it easier to decide what to do and how to best do it.
Holiness is about our abiding in Christ and reflecting His love. Whatever behaviors fall by the way side are largely unnoticed except when mentioned in passing.