The law courts can be full of innocent people when man gets hold of the law. History has proven this to be so, especially if driven by fanatical element's.
In the end we have to ask ourselves what laws are from the Prophets and the Messengers, the laws we are to submit to and what is from man's own law?
Then we must consider, can God change the Laws?
Regards Tony
This is indeed an important point when studying Shariah, which has the aim to understand God's Will and Recommendations:
to discern the important from the details,
to discern situation dependent advise from universal principles,
to discern an insignificant remark of a prophet from divine advice,
to evaluate the significance and the reliability of a tradition in the frame of the whole.
The majority opinion of the ulema is not necessarily correct as many follow the (man-made) rules of their Madhab without such background consideration.
Can God change the laws?
We can only observe whether God does change the laws; we cannot know what changes may be possible if God wills.
It seems that God does not change the natural laws.
God did modify His recommendations, which are seen as prescriptions or laws to the believers.
There are explicit changes from Judaism to Islam which are marked as such in the Quran and reliable Ahadith, e.g. the abolition of Shabbat and the introduction of 5 instead of 3 daily prayers, and the restriction of death penalty to three cases in non -martial law (rape, adultery murder).
I see the conditions of the execution formulated by the Muslim scholars critically: Jesus, according to a rather weak tradition, spoke a conditional penalty to an adultress whereas Muslim scholars consider it obligatory to execute provided that the harsh conditions of proof are fulfilled. The look on the prior revelation may modify the understanding of God's recommendations.
Alike, as you accept two more prophets, you should still consider whether the prior messages are really changed.