Sarah was half-sister of Abraham?

[Anomalocaris]

I thought Christians believed in absolute and objective morals, set in place by an unchanging god.

Are morals objective and absolute or are they not?

Noope.

Morals are the ever changing standard of Man.

God's 'brand of Morality' Is refered to in the bible as Righteousness. God's righteousness is whatever He says it is. When ever He says it. The acts themselves mean nothing. For in just about every case where we have a 'thou shalt not,' there is an exception to the rule. (A Time or place where what God would normally considered to be a sin is either commanded or permitted.)

You've confused the fact that God is the same yesterday, today and tomorrow with the idea that man's everychanging morality is somehow linked or God is bound to a standard of 'morality' of your own making. Ironically if He were then He would not be God.

I am right because I said god said so and I said god is right because I said right is what god does. Really? So the incestuously begotten resorts to his one and only trick of argument by flippant and yet convoluted redefinition? Who would have thunk?