On Moral Authorities

[Ignorant]

Erm... Sexual Abuse will always be immoral, for it is against God's will which is unchanging. So, it is based from God and not based from people.

It is not true that if well being and God's will are the same, then God is entirely irrelevant, for we can argue soundly that the source of well being is God. So, if there's no God, then there's no well being. But, there is God, per sound theistic arguments like the Five Ways of St. Thomas Aquinas. To deny the conclusions in Five Ways that God exists is to both deny things which are evident, (for the Five Ways starts with the things that are evident), and to deny laws of logic (for the Five Ways utilized valid logical forms).

But who is telling us what is god's will? ... 

Theologian can answer for himself, but I liked the question, so I will offer a short answer:

"God's will" is found in "what" we and other things are, as well as the relationships that exist between them. God's will is not an external list of rules floating somewhere out in the aether or contained only in a specific collection of texts.

Acting according to what-you-are, who-you-are, what-and-who-other-things-are, and how-other-things-relate-to-what-and-who-you-are = God's will. 

That requires the truth of what-you-are, who-you-are, what-and-who-other-things-are, and how-other-things-relate-to-what-and-who-you-are

AND

It requires desire and capacity (i.e. a will) of the goods that correspond to and bring about the truth which you know into reality through action.

The more your desires correspond to the truth about the goods goodness of these things, and the more your knowledge and desires are directed/translated through your actions by your will into reality, the more freely you are living God's will.