Where did Morality come from.

But that's just it. Harm to the other person, whether it affected you or not, is still bad. But why? Why is it bad? 

Imagine you are in paradise (meaning a place where everything is perfect) with another person. You have no reason to kill that person, but you also don't have any reason to not kill that person. Killing them wouldn't affect your survival, or the state of thriving that you are in. Nothing would change, except for that person dying. 

Now be honest. Killing in this situation would be a (so to say) sinful thing to do, or a bad thing to do obviously. But why would it be bad? After all, nothing bad would happen except for that person losing paradise.

Morality is something that all humans possess. People say that we have a sense of morality imbedded in us. Others say that we only have morals, for the goal of survival, and thriving. 

I believe that Morality is a distinctively human trait. Sure, other animals and creatures hold some sort of kindness and generosity for certain things, but those creatures have been proven to do it for survival or thriving.

But we are different. 

But that's just it. Harm to the other person, whether it affected you or not, is still bad. But why? Why is it bad? 

Because God says it’s bad?

The most common response I get to a question like that is "God's plan and wisdom is ineffable."

I think it's an excuse not to understand the world around us or comprehend why things work. For most people it's simpler to just claim it incomprehensible.

Why is killing someone else wrong? Well, do you want to be killed? If not, there’s your answer.

Morality isn’t a product of our instinct to survive, our survival is a product of our inherent moral system.

So a simple conclusion would be.......Moral is, as moral chooses.

You either accept that its wrong to decrease life, either you dont.

You either accept that its wrong to increase pain, either you dont.

Right, it wouldn't be.

The problem is that in this world it is a bad thing. 

Humans exhibits ethical behavior by nature because their biological makeup determines the presence of the three necessary, and jointly sufficient, conditions for ethical behavior: (i) the ability to anticipate the consequences of one's own actions; (ii) the ability to make value judgements; and (iii) the ability to choose between alternative courses of action. Ethical behavior came about in evolution not because it is adaptive in itself, but as a necessary consequence of man's eminent intellectual abilities, which are an attribute directly promoted by natural selection.

But why are those things wrong, and not good?

Thats not a logical answer. Thats just you assuming that two different people are same person. It’s just an appeal to virtue of justice.

So you reject teleology, that says how the cause of something is also its result?

For example, morality is caused by that morality causes us to survive, and survival is caused by morality.

If you however don’t care whether a stranger comes up to you and kills you

I agree. However, I thought giving you a view into their perspective might help you better understand who you're talking to and how the conversation might proceed. Sometimes it's better to recognize early on in a conversation that a person is incapable of accepting a certain view rather than doing what I have in the past and continuing to think it is possible. Religion is a very sensitive thing mostly to do with its incredible association with emotion and can be overpowering when it comes to logic or empirical evidence. For myself, I often keep the two separate and do not ask someone to explain common sense of their religion. Do as you will, I was merely providing something potentially insightful.