I think my issue with it is this, take democracy in the US for example, it started out somewhat pure and good. Through time more and more people have tampered with it and now it is not as good. If you were to incorporate a religion into that, and then the religion would become corrupt over time as well, and at the fault of man, not just the rulers, but all men. I would rather have a bad man rule with man made law, than a bad man rule with the law of God. I guess maybe it is the less of the two evils, I think it is just a matter of opinion.
Islaam isn't tampered with, there have been many attempts to tamper it for over 14 centuries now, yet the authentic teachings still remain preserved and intact till today. And it will remain this way till the Day of Ressurection because Allaah Almighty says:
We have, without doubt, sent down the Message; and We will assuredly guard it (from corruption). [Qur'an 15:9]
If you believe that God is more just than man, then you can agree that God's laws are better than man made laws. However, if you believe that man's laws are greater then God's - then you need to question your faith in God.
Stoning someone to death in todays world is wrong, we are supposed to be a little more humane than that by now. You saying that this is condoned in Islam implicates that Islam is indeed a violent religion. There is no need to gather around and stone and kick a woman to death, and I dont care what she did, it is a disgusting sick act of violence. Not to mention look at those peoples faces doing it, they laugh and smile. I think this effects the heart in a much more profound way than being cheated on by a spouse, I believe it turns the heart black. And as for beating children in America, you can give your kid a good whipping, you just cant draw blood or leave bruises. It is a matter of knowing your strength and the strength of a child, although people who would allow the stoning of a woman would probably not get this. Some children are not respectful because they are not taught respect, not because they werent beat enough, you can teach something to someone without physically beating it into them, this again shows you 10th century mindset.
According to christianity, the punishment for apostasy is death, but not just that - its actually stoning to death:
Deuteronomy
Chapter 13
KJV
1 If there arise among you a prophet, or a dreamer of dreams, and giveth thee a sign or a wonder, 2 And the sign or the wonder come to pass, whereof he spake unto thee, saying, Let us go after other gods, which thou hast not known, and let us serve them; 3 Thou shalt not hearken unto the words of that prophet, or that dreamer of dreams: for the LORD your God proveth you, to know whether ye love the LORD your God with all your heart and with all your soul. 4 Ye shall walk after the LORD your God, and fear him, and keep his commandments, and obey his voice, and ye shall serve him, and cleave unto him. 5 And that prophet, or that dreamer of dreams, shall be put to death; because he hath spoken to turn you away from the LORD your God, which brought you out of the land of Egypt, and redeemed you out of the house of bondage, to thrust thee out of the way which the LORD thy God commanded thee to walk in. So shalt thou put the evil away from the midst of thee.
6 If thy brother, the son of thy mother, or thy son, or thy daughter, or the wife of thy bosom, or thy friend, which is as thine own soul, entice thee secretly, saying, Let us go and serve other gods, which thou hast not known, thou, nor thy fathers; 7 Namely, of the gods of the people which are round about you, nigh unto thee, or far off from thee, from the one end of the earth even unto the other end of the earth; 8 Thou shalt not consent unto him, nor hearken unto him; neither shall thine eye pity him, neither shalt thou spare, neither shalt thou conceal him: 9 But thou shalt surely kill him; thine hand shall be first upon him to put him to death, and afterwards the hand of all the people. 10 And thou shalt stone him with stones, that he die; because he hath sought to thrust thee away from the LORD thy God, which brought thee out of the land of Egypt, from the house of bondage. 11 And all Israel shall hear, and fear, and shall do no more any such wickedness as this is among you.
If you've noticed, the most justice in history has to be at the time of the Messenger of God, peace be upon him. And at the time of the guided Khulafah, his companions and successors. You know why? Because the evil doers never felt they could get away from their crimes. A guy couldn't rape a woman with the hope of being released from jail within 2yrs, rather he would fear facing death - so he wouldn't approach that evil. Nor would anyone murder, compared to the amount of murders commited today - why? Because he feared death also.
The laws of God are for the benefit of mankind, they're not for the benefit of the 'who can get the most toys' society. Again, you have to question whether God could truelly send a way of life and guidance for all of mankind, since God has power over all things.
If you disagree - you have to question your faith in God. If you feel that christianity isn't doing a good job of it, then theres probably an alternative which hasn't been corrupted, since the authentic teachings of Islaam have been preserved for more than a millenium - all by the Grace of the Most Compassionate, All Knowing, the Wise.
Regards.