Go back to Genesis 3, where enters the nemesis of man, Satan, who deceived Eve, who lured Adam into believing Satan, that God was withholding something from them that was to their benefit to have. They lost ownership of the planet at that point, and Satan gained it. You can read about Satan and the war in heaven in Revelation 12, Isaiah 14 and Ezekiel 28. OF course God knew it would happen, because He knows the beginning from the end. But God wants His creatures to serve Him out of love, not fear. Satan brought up the question of why do His creatures need rules (laws) to rule them. They (supposedly) know how to behave well and respect one another. But Satan also had other ambitions. He coveted the worship that is owed to God alone. The angels, and even Adam and Eve, had never been exposed to lies before Satan came along and planted doubts and questions in their minds. Satan and his followers were kicked out of heaven, and quarantined on this planet. God has allowed Satan to carry out his plans here to show the watching universe what the universe would be like if Satan had his way and law was thrown out, and everyone did what was right in his own heart. Us humans got stuck in the middle of this cosmic conflict. Satan continues to deceive humans with all kinds of religious ideas, many which involve worshipping fallen angels posing as "demi-gods" or pagan gods, and sacrificing humans to please these demi-gods. When Satan couldn't destroy God because of his isolation on this planet, he turned his wrath on God's children, and has been destroying humans, the environment, animals, etc. and getting humans to destroy themselves and disqualify themselves from heaven with their sinful practices. Religion has become twisted to serve the desires of sinful men instead of a holy God. Satan wants humans to believe God is evil, and he himself is just misunderstood and treated unfairly. Satan has convinced many humans, and their religious institutions, that God is cruel and arbitrary and loves suffering and death. But this is really what Satan is like, not God. As for so many different religions, look how Satan has managed to get God's children to argue amongst themselves, to believe only what they see and feel. God is portrayed among the various religions as having conflicting personalities and desires. The God called Allah is not the same as the God called Jehovah. The blame may be that the writers of the Quaran and the Bible and the Torah had different personal experiences with their prophets. And there are so many denominations, even in among Christians, because believers hear something good from one religious leader, and cling to that philosophy, and only that, and refuse to grow beyond that.