God created a perfect world. When Adam knowingly disobeyed God and sinned, then sin entered the world through Adam. Eve was tricked by the serpent (Satan). That is why sin is passed down through the man. Jesus Christ is referred to as the seed of the woman, because He was conceived by the Holy Spirit. Anyway, God created Adam and Eve in innocence, but when they ate from the tree of knowledge which God told Adam not to do, then their eyes were opened and they knew good and evil. So it is man who chooses evil. Does God allow it? Yes, God gave man a free will. God could have easily created man to worship Him, but He wants us to love and worship Him because we want to, not because we have to. God created the angels and gave them free will, too. Lucifer (Satan) and his co-horts (demons) chose to rebel and are now fallen angels who will eventually be cast into hell with all unbelievers. From Adam until now, the effects of sin have gotten progressively worse and will continue to do so until the Lord returns. God allows evil for His divine purpose, and I believe that is to bring us to Christ. Right now the Holy Spirit is restraining evil to a certain extent. There will come a time, and that time is imminent, that Christ will snatch (Rapture) the true believers from this world. When that happens, then the Holy Spirit will no longer restrain evil and God will bring judgment on an unbelieving world. This is the time known as the Tribualtion. It will last for 7 years and will commence after the Rapture and with the signing of a peace treaty between the Anti-Christ and Israel. The Tribulation is also the time when God will be dealing mainly with the Jews once again to bring them to their Messiah. There will be 144,000 Jews from each of the 12 tribes that God will seal during this time and they will be preaching the gospel. The Tribulation will be worse than any time in history. Much of the world and the population will be destroyed. During the first three and a half years of the Tribulation, the Jews will be allowed to worship in the Temple in Jerusalem (which will be rebuilt). After three and a half years at the mid-point of the Tribulation, the Anti-Christ will declare himself to be god. It will be required that anyone who wants to buy and sell will have to take a mark on their forehead or hand. Once you take this mark you can never be saved. At the end of the Tribulation, the armies of the world will come against Israel in the valley of Megiddo (Armageddon). Christ will return with His saints (believers) and He will destroy the enemies of God and Israel. All the Jews who are alive at this time will see Christ return and accept Him as their Messiah and Saviour. After this, all believers will go into the Kingdom for 1000 years. Satan will be bound during this time. Those believers who go into the Kingdom in their physical bodies will have children and they will have to come to Christ (who will be ruling on the throne of David in the Millennial Temple in Jerusalem) for salvation. All other believers (OT saints, NT saints, Trib saints who died during the Trib) will have a spiritual body. At the end of the Kingdom, Satan will be loosed to lead a rebellion but it will be brief. It's hard to believe that even then people will reject Christ, but they will. Then Satan will be cast into hell, and Christ will judge all unbelievers according to their works since they rejected Him and chose to be judged by their works. All unbelievers will be cast into hell and all believers will go into eternity with Christ in a new heaven and a new earth. This is just a brief overview, but can all be found in the bible. If you choose not to believe it, then that is your choice. My prayer for you is that you will seek after God with all your heart and ask Him if it is true.