Apologists for Muhammad
Many apologists for Islam explain that Arabian culture of the 6th century was very violent and the environment was very harsh and it was difficult to survive and Muhammad's rules and regulations, inhumane and disgusting as we now see them, were as good as you could get in that time and place.
But Jesus lived 5 centuries before Muhammad in a place racked by civil unrest, poverty and military rule where the standard punishment for speaking out against the Romans was crucifixion and the real Pontius Pilate was finally sacked, not because he ordered the death of innocent bystanders, but because he ordered the death of too many innocent bystanders. Even the Romans had limits on butchery.
Gautama Buddha lived at a time and place where life was so hard that he saw poverty, disease and death on his first walk outside the palace and his father didn't become a king because he was a lovely pacifist, nobody ever has. Jesus and Buddha preached a positive message despite their times but then they weren't Muhammad. The penalty for an adulterous woman in Palestine in the time of Jesus was stoning to death. An adulterous woman was brought to Jesus and he was asked what should be done, he said "Let him without sin cast the first stone" or something similar.
A crowd watch a man and a woman being stoned to death for adultery in Manbij, Syria
The definitive Quran text says adulterers should be whipped 100 times but these days we've all heard of women being executed for adultery or for being raped. We can even watch it on the TV or Youtube because Muhammad said adulterers should be whipped 100 lashes and then stoned to death. This is recorded in Book 17 of the respected, canonical collection of hadith, the Sahih Muslim. It's called The Book Pertaining to Punishments Prescribed by Islam (Kitab Al-Hudud). It makes for very interesting reading. By the way they use rocks, not stones.
Within a year of his arrival in Yathrib, he ordered the stoning of two Jews caught in adultery. They evidently were converts who belonged to one of the Arab tribes that Muhammad claimed jurisdiction over. Rabbis argued for mercy, but to no avail. They were taken outside of Muhammad's mosque and a crowd stoned them to death. It is said that the man bent over the woman to protect her from the stones. - It's All About Muhammad by F. W. Burleigh
An adulterer being stoned to death for adultery in Somalia