I do think it is very unhelpful to speak about "absolute" morals and then go right on and explain it in terms of relative morality.
I think you need to distinguish between - absolute, relative, and objective morality.
Absolute morality does not exist unless your first presuppose that there is an ultimate lawgiver and that she/he has communicated those ethics in a way we can access reliably.
The fact that no two christians can agree on anything proves that absolute morality fails.
Absolute morality also raises a more difficult problem. Does the deity decree declare something to be good because it is good or is it good because she/he says it is?
If the former then morality is separate from god and something to which god must be subject.
If the latter then god could decree anything to be good. This is what we find in the bible. If god says so then infanticide, kidnap and slavery are good under certain circumstances. This puzzle, called the Euthyphro dilemma, has defied resolution since Plato.
In practice then absolute morality, far from providing a solid base for ethics, turns out to be capricious. It is morality by divine fiat.