The central message is the same of all divinely-inspired religions

Question: Where do you think that the Holy Books of the other world religionsand belief systems came from ? Are they incomplete books written bysincere persons who thought that they knew what God wanted them to write, but failed to correctly understand. Or are they simply theproduct of cunning human minds seeking power and influence?

Answer: In the very beginning of the Quran, we are told that:
http://searchtruth.com/chapter_display.php?chapter=2&translator=4
1. Alif. Lam. Mim
2.This is the Scripture whereof there is no doubt, a guidance unto those who ward off (evil).
3.Who believe in the Unseen, and establish worship, and spend of that We have bestowed upon them;
4And who believe in that which is revealed unto thee (Muhammad) and that which was revealed before thee, and are certain of the Hereafter.
5These depend on guidance from their Lord. These are the successful.
So, you see, we are required to believe in all the sacred, holy books of religions before Islam as the source and message were essentially the same…… Allah sent His messengers from time to time to guide humanity. What happened, we believe, is that, with time, part or most of the essential message was lost, varying from nation to nation, people to people. The Holy Books came to contain a mixture of Divine revelation and human interpolation. The result was a parting of ways from the original, true spirit and teachings of the Prophets. The Quran came as a confirmation of the prophets and prophecies of old, and as a ‘sift or seive’…. To distinguish between ‘the truth and the false’ in what people among different religions had come to believe. Thus, you will find, in the Quran, mention of the prophets of old, but how and what the Quran relates is quite different from accounts given in the other scriptures. Sometime earlier, a muslim brother had posted the passages about Prophet Jesus……….. did you read it? Wasn’t it so different?Also, reading any of the divine books, whether it is the Old Testament, the New Testament, the Vedas, etc, doesn’t the radiance, the brilliant sparkle of the divine message shine through certain verses, while at other places one wonders could the Prophets or God/gods have spoken and behaved so and so, can this actually be true, is this actually of divine origin? Whereas, when you read the Holy Quran, morally and ethically it is so sound, so perfect, and all Prophets have been mentioned with such respect that…. it is so easy to believe in it!
So, Yes, the central message is essentially the same of all divinely-inspired religions.