So lets look at the army that went to Mecca on the way the Prophet Muhammad (peace and blessings of God be upon him) saw a dog giving birth. He instructed a soldier to guard the dog and prevent it from being distrubed.
When he entered the city, he was riding a donkey, with his head bowed in such a manner that his beard touched the back of the donkey.
He made a decleartion that anyone who entered into the house of Abu Sufyan was safe from harm. Abu Sufyan was his enemy who had fought against him for 20 years, had killed many muslims and the Prophet said anyone who enters the house of my greastest enemy is safe! Does this sound like a normal person to you?
There was little resistance in fact only those who had killed muslims were put to death.
In any country when a city is sacked its inhabitants are put to the sword or massacred. These were all people who had fought him for over 20 years.
When they gathered, He asked them, "what do you think I shall do to you?" They said, "O noble one son of a noble man be just that." He replied, "I will say to what Joseph said to his brothers there is no reprisal upon you today. you are free to go." No mass killings. If a nation fought you for 20 years who you just let them go? Any normal person would've killed them.
Many of them became muslims because of this.
The sacred law is about the rights of God and these cannot be disobeyed - if they are then the societies go to ruin. If you look at western societies then the lack of rulings in terms of illegal fornication leads to all sorts of problems. Children dont know their fathers are and children are abandoned so forth.
If a case is taken to a judge then you don't expect the judge to forgive the person do you. You expect that the person is punished same here.
Read the whole story with an open mind then it'll all fall into place start with Muhammad: based upon his earlist sources by Martin lings.