The Quran was revealed to the Prophet Muhammad
by the Angel Gabriel. The Quran is the Word of Allah the Most high. Other Prophets were given books revealed to them by Allah, again through the Angel Gabriel. However, the Quran is the final revelation that we must follow. - The other books were corrupted and changed... The Quran is a miracle of Allah that will remain preserved till the day of judgement.
Story of ISaac Ismael ? 
oh, I will write that here soon.
why do Christians call God " Jehovah" or "Yahweh"?
Here you can find your answer inshaAllah
http://www.turntoislam.com/forum/showthread.php?t=1053
(link broken, I will fix later inshaAllah)
why do we fast?
FAsting is an act of worship that all the Prophets of Allah would do. This includes the last and final messenger Muhammad
. It is a means of getting close to Allah, have our sins forgiven, increase our rememberance of Allah, develop our love for Allah, and to have Allahs mercy. There are countless benefits. We fast, due to Allah's command in the Quran to fast.
why is Muhammed(pbuh) referred to as the Holy Prophet, and are all prophets referred to as this?
All the Prophets sent to mankind are much loved and respected. The Prophet Muhammad was the best of the Prophets due to his being chosen as the last and final messenger by Allah. However, we do not disrespect or not love the other Prophets. We love them greatly. We are closer to the other Prophets, Muslims are closer to Jesus then anyone else due to the fact we believe and worship Allah without associating any partners to him. We do not blaspheme by saying Jesus is one of three or son of god.. or even God. Nor do we say he died on the cross. These things are what make Christians distant from Jesus. For they are not following his teachings.
Each of the Prophets was a Muslim, a person who submits themselves to Allah without associating partners to him.
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Are there any holy spirit?
No not like in the Christian beliefs, in the Quran only the Angel Gabriel (Ruh al Qudus) visited Maryam (Alayhasalam), to tell her about the good fortune of her new born son and her virgin birth. As a gift and mercy from Allah.
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do muslims believe in evolution?
Humans are not descneded from apes. We all come from Adam Alayhisalam. Evolution is a
theory with many holes in it. The Christian stance is different than Muslim stance. For we know and accept that the earth is billions of years old. Whereas Christians limit themselves to believing the earth was made when Adam alayhisalam was created. However, Muslim believe earth was created before Adam Alayhisalam, and that Allah put the Jinn on the earth before mankind. The Earth was not created solely for man. Allah knows best about some natural changes in animals. But, to say humans come from apes etc, this is not true.
is there a "sabbath" in islam?
The Muslim holy day is the Friday. It is not a day of rest, we work and continue as usual. However, we should make Ghusl (Islamic ritual bath), cut our nails, read some chapters from Quran (recommended Surah Kahf) and attend the Mosque for the Juma (Friday Sermon and prayer, the sermon is usually 20-30mins and recommended to be kept short by the Prophet
and the prayer replaces the Zohr prayer, and is just 2 units).
how is islam a peaceful religion if there are so many violent passages in the Qur'an?
There are no "violent" passages in the Quran. The Quran is a mercy upon mankind. The verses to do with fighting are in a specific context, which were revelaed when the Muslims were facing various adversaries and were in hostile times. Any verses to do with Jihad must be read together and in complete form. Alhamdulillah. Muslims who understand Islam know that we must be good to other people no matter their race, nationality, gender, religion.
There are many many places in the Quran and in the hadith calling Muslims to be peaceful, tolerant and kind to those people we are at peace with.
Islam does not rule out defending ourselves, our lands and our people from oppression. One must understand the pure context and teachings of Islam. The enemies of Islam try their best to write and preach hatred and propoganda against Muslims, so we must be careful.
was Jesus(pbuh) raised to heaven and still lives and will comedown, die and then be lifted again to heaven one day, or did he die and God brought him to heaven?
Jesus was raised to heaven, he was not crucified. He is alive and he is in heaven. He will come down to lead the Muslims. He will follow and rule according to the Quran and the message of the Prophet Muhammad
. He will smash the crosses and the people will come together to accept Islam and submit themselves to worshipping Allah alone. And he will die naturally.
also was the Devil a fallen angel who was kicked out of Heaven or was he a jinn?
The Devil, Iblis was not an angel. Rather he was the King of the Jinn. Jinn are another race Allah created out of fire. They are commanded to worship Allah alone. Iblis was outcast and sent to earth, but he was not an angel.
Perhaps if i get time, I will add various more content and evidences to this post inshaAllah. A lot of questions
