Answer
Comparison could be done only in similar things. These two religions contradict in basic belief of God. It is not possible to compare them by factually.
Can conclude with the following aspects. The both are religions, started from Middle East, a large number of people are following the beliefs of that religions. The both religion have their own books Quran and Bible. The followers are using their church and Masjids to worship according to their beliefs. These two have some faiths in common such as creation of Universe in six days, creation of Adam from dust and Eve from Adam's rib, Hell and heaven, Jesus coming etc..
Christianity and Islam share a common history and share some of the same beliefs, but they have definite differences...
Christianity and Islam.
A good way to start a conclusion is by summing up how even though these two things ( whatever you are comparing and contrasting) had many similarity's and differences, they still did well. (or whatever your topic is about.)
That's like asking why did Christianity start in Jerusalem?
Abrahamic religions include Judaism, Christianity, Islam and the Baha'i faith. Christianity recognize Judaism but not Islam. Islam recognizes Judaism, Christianity but not Baha'i faith. And finally Baha'i faith recognizes Judaism, Christianity and Islam all together. And obviously he did not start anything. He simply preached the word of God, i.e. the holy revelations.
answer1. Islam started in 600-800 CE2. Christianity sarted in 20-200 CE3. judaism stated 4000 years agoanswerActually, the previous answer doesn't say where these religions started.Judaism and Christianity started in Israel. Islam started in Saudi Arabia.
For Judaism, this link has the details:http://judaism.answers.com/jewish-history/a-biography-of-abraham
Allah (or God and same God worshiped in Christianity and Judaism) started Islam religion before and by start of universe creation. Refer to question below.
Islam religion originated by Allah (or God in English and same God worshiped in Judaism and Christianity) by start of universe creation. Refer to question below for details.
There are numerous religions that started in the Middle East such as the Kemetic, Akkadian, and Babylonian faith among many other polytheistic creeds. All three monotheistic religions, Judaism, Christianity, and Islam, also started in the Middle East.
Islam means submission and surrender to Allah (God in English and same God worshiped in Christianity and Judaism). In this sense Islam is religion with the same name since start of universe creation. Refer to question below.
Islam started by start of universe creation. Islam means submission and surrender to Allah (god in English and same God for Christians and Jews). Accordingly, all God creatures are created on full submission (or Islam) to God as the one and only one God. God prophets were sent by God to convey Islam message to mankind. So, all God prophets; since Adam through Noah, Abraham, Moses, Jesus and Muhammad; are calling to Islam in the sense of God worship as the one and only one God with no partner, no father, no son, no companion, no associate, and no equivalence. Islam per God revelation of Torah to Moses is called Judaism. Islam per God revelation of the Bible to Jesus is called Christianity. Islam per God revelation of Quran to Muhammad is called the same name Islam. Prophet Muhammad called to Islam per Quran revelation to him in year 610 AD.