Christian ethics is as simple as this: love God, love others.
Everything else is commentary.
Physical abuse, sexual abuse, financial abuse, verbal and mental abuse, these are all spoken against by Jesus and the prophets as they violate the command to love others. This command is pretty open ended too, extending even to enemies (see Matthew 5:43-48) and nonhuman others (see Proverbs 12:10). If, in your practice and teaching of Christian ethics, you forget to love others, you’ve missed the point.
The corollary to this is loving God. If even our enemies, who’ve done nothing to bless us, are to be treated in loving ways, how much more should we treat God, who’s the source of all blessing, with love and respect? When we misrepresent God, intentionally or otherwise, or try to turn God into a mascot to serve our own purposes, is that not a form of abuse too? Indeed it is, and quite a serious form of abuse when you think carefully about it. God is so foundational. Unfortunately that’s all too common, even amongst those who claim to love God. That’s missing the point too.
But there’s another way we can miss the point. If our motivation to love God and love others is based on what we get out of it ourselves, if it’s based on some sort of gaining idea, whether a desire for salvation, or even something as innocuous as a good feeling, we’ve missed the point again. True love is a giving orientation, not a gaining orientation. We’re already loved by God; we should love just because. In Christian ethics, rules should be understood within the context of relationship; our behaviour should be an extension of our beholding of God. Love without holding back, because love is what it is.