Dear Vinod Parbharkar,
Religions often include some empty rituals, worshiping a god or a group of deities, having a personal 'spiritual' connection with god etc. So religion are almost same.
The question is that are religions right?
The answer is No. For conveying the manual of life to mankind (basic standards, permanent moral values), God sent His messengers to all nations and lands in the past. Unfortunately people adulterated the messages and all the scriptures, and they created man-made beliefs called religions.
What about the Quran?
A: Humans always need a standard of values (you can find the reasons of it in the following books), so God sent the Quran to His last messenger, and He guaranteed its preservation.
The Quran, just like the original books of the other messengers, does not teach religion, but it teaches us the right way of life, some simple standards for having a good personal & social life, the Deen.
I strongly recommend the following books to you:
- Islam As I Understand, Who Wrote The Quran, Thus Speaks The Quran, and The Quran As It Explains Itself by Dr. Shabbir Ahmed (you can find these books at free library of Ourbeacon.com)
- Adam O Iblees by Ghulam Ahmad Parwez
(you can find it here: http://www.galaxydastak.com/cgi-bin/bbs60x/webbbs_config.pl/page/1/md/read/id/314123119260609)
Your quote: "I hear from priests of every religion saying that their religion is best."
- You will find the fact for yourself after reading these books.