There are a lot of topics and I don't want to be here for an hour, so I will be brief.
There are exceptions to "killing is wrong" as many will agree; but the bottom line is that killing others takes something from them that is not ours to take. It hurts people.
Stealing is wrong because it is ultimately dishonest and takes something from another that is not yours to take. It hurts people.
Children need guidance of those older and wiser. Children need adult supervision for their survival. Children need to be taught the rules of society so that they can exist within those rules and have a good life.
Bearing false witness ruins another person's reputation and life. It hurts people.
Sexual abuse is wrong because it hurts people.
Where polygamy is practiced, there is a direct correlation to misogyny and denial of women's rights. There seems to be a correlation here that is difficult to ignore. I value "informed consent" so it can be successfully argued that if all members were consensual to this arrangement, another has no right to tell them they can't live this way. I'd like to subscribe to that idea, but not until there is a way to unlink the link so explained.
Fidelity and faithfulness builds trust and happy, healthy marriages. People in these arrangements tend to be happier.
IN short, if everyone pursued these values, the world would be a better place.
It hurts people and other living creatures.
I find it curious that the moral outrage against homosexuality can not be explained without invoking religion, yet so many still insist it is immoral.
I know atheists who regard the practice as filthy and reprehensible, immoral.
Without a standard of morality commonly agreed to, the idea of morality becomes irrelevant. It is purely an individual evaluation, for the individual, with no bearing on society as a whole. Morality becomes a very weak consideration regarding behavior, in fact, society becomes more and more amoral.
Consider abortion, as an example. Once considered wrong and immoral at any stage during a pregnancy, it became morally acceptable in the early stages, then at anytime between conception and complete birth, and now many, including the governor of one state, support infanticide.
Moral and immoral are becoming, for society as a whole, meaningless terms. The new reality of self gratification and individual morality has taken us down the rabbit hole where up is down, blue is red, and left is right, or not.
So, you propose that using an organ designed or evolved to expel waste from the body in a sexual way is not immoral without a religious perspective to it. So what ?
Is it immoral to eat ground glass ? Why ?
We who accept Christian morality hold to the immorality of a variety of things, lying, gluttony, homosexuality to name a few. Yet we can only judge these things within the boundaries of believers. Believers who voluntarily agree to hold to these moral standards, and are free to leave if the required behavior becomes too rigorous.
We have no responsibility to judge the legal behavior of individuals outside the church, and it is wrong to do so.
What I don´t understand is why some feel compelled to continually beat this dead horse. If you have decided that you will not live by the rules of the New Testament, that is your problem, not mine. It only becomes relevant to me if you are a Church member.
I often wonder if this continual rehashing of homosexuality, or homosexuality v. Christianity/Judaism is a form of reassurance to those who worry about the morality of what they choose, or support.