There is no doubt that the Qur'an and Ahadith (sayings attributed to Muhammad) will contain some very good advice for mankind - but this is also found in many other questionable religions that teach morality, an afterlife of eternity, and an ultimate Divine Justice that will reward those who do good and punish those who do evil. The similarity that Islam has with Judaism and Christianity is that all three are monotheistic religions; belief that only one God exists as Supreme Creator of all. From that point forward, the teachings drastically come to a parting of ways.
Muhammad's "angelic revelation," proclaiming him to be the final messenger of God and introducing Islam as the "true religion," occurred 610 years after the life and ministry of Jesus Christ. While Muhammad proclaimed that Jesus was a prophet sent only to the Jewish people, he negated the fundamental Christian belief that Jesus was the Son of God and Saviour whose crucifixion on the cross atones for the sins of all mankind. In addition, the Qur'an also conflicts theologically with the Torah of Judaism in areas of Creation and the recorded accounts of God's messages to the Prophets. In one fell swoop, Muhammad's "new message" declared that Jews and Christians had erred from truth and that his mission was to convert the entire world back into submission to Allah.
With these instructions, Muhammad gave orders to destroy all pagan idols that were established within the Ka'ba except for a black stone that had been placed there a few years prior to his first revelation. (The stone is believed to be a meteorite.) From that point on, pagan tribes were forced to denounce their idols and worship Allah; any who refused were killed. Jews and Christians of that time period also came under persecution to convert to Islam and those who didn't had a heavy tax imposed upon them as long as they lived within Muslim-controlled territory.