If you are referring to Muhammad then yes - those events almost all took place in what is now Saudi Arabia and Iraq. However following his death the religion basically was regulated from two epicenters: Baghdad and Damascus.
Sorry, I've been wondering how to phrase this so that I don't mistakenly come off as a jerk.. Do you have any evidence other than churches and sightseeing being preserved in Turkey? I say this because the oldest mosque, the Kaaba, and the Temple of Solomon/Al Aqsa mosque are far more central to any of these religions. I believe you'll find that several churches in Africa claim that they were the first as well. A huge chunk of Islamic scripture was found in southern Yemen. Tons of Christian scripture was found in Egypt. The Prophet PBUH is buried in Madinah in Saudi Arabia and he is from Makkah. I saw with my own two eyes the cave where most of the Quraan was revealed to him. His house and his mosque are preserved. The exact dimensions of his house (square feet, height, number of rooms, number of doors) is known to us. Turkey has always been influential. I'm sure the rulers later on had significant influence on Islamic theory (generally speaking). But to say the center of Islam is in Turkey... That is just false. There are no ands, ifs or buts about it. You can argue forever that its monuments have been preserved better in Turkey (I disagree), but the center of Islam is undoubtedly in the Arabian Gulf. Personally, I believe Christianity and Judaism are somewhere between Egypt and Iraq. Turkey is significant because it is the gateway to Europe. It is the meeting point of what was then considered two sides of the world. There was political strength, milltary strength, high level of education so naturally Islam became a huge draw there when (for better or worse) its influence became apparent. In all honesty though, I am so open to discussion. I love this kind of stuff. I love weeding out things from my religion which were inaccurately passed down. I would seriously (NO SARCASM) love to see some strong reasoning behind your definitve claim that "Turkey is considered the birthplace of the major religions of Islam, Christianity and Judaism." I think it is prudent to preface that sentence with "I believe". Because that would indicate that at least a majority of the world agrees with you and I can assure you that there are no less than 3 billion who disagree with you.
You do not seem like a jerk at all. I obviously have a lot to learn on the subject and I enjoy these debates as well. In retrospect my phrase should have been something about the central role Turkey played in all three of these religions that allowed them to flourish beyond the places they were conceived from around the 2nd century all the way through the 17th. Keep on teachin'! I'm listening and learning.