Wow, pretty ignorant comment, and I know better than to feed the trolls, but...
Muslims don't claim "exclusive self-correctness/righteousness", rather God has told us in the Qur'aan that anyone who believes in Him Alone without associating partners, and His Messengers and the Last Day will have their reward with God.
However, most people, including majority of Muslims will enter hellfire first (God knows best who and how many), that includes anyone who prays, fasts, does charitable deeds, etc. Because of other sins and selfishness, and taking advantages of others, killing, etc, but especially doing good deeds to show-off (which is a form of associating partners with God).
Islam came to supplant other religions/way of life, as God tells us in the Qur'aan that many (countless) Messengers and Prophets have been sent before, including Moses and Jesus, but their message was only meant for their people for a few generations before another Warner was sent. The first Prophet was Adam (to his own children), and the last being Muhammad (to all generations).
If praying gets you to heaven, then god dammit, pray fucking continuously till you starve and die and go to heaven sooner
Perhaps that message would be more fittingly directed towards Buddhists and Monks?
No religion or Warner came after Islam and Muhammad because God told us explicitly that this would be the final message to humanity and final Prophet.
However, we (like the Christian, and some-what Jews) also believe that Jesus will return to re-establish peace and once again correct people who had deviated away from the straight path.
You would do justice to your own self and your soul by reading the Qur'aan with an open mind, but more importantly, open heart. As the Qur'aan states, "God doesn't guide the criminals, rebellious, and hard-hearted people".
If you want to know the real life of Muhammad as based on evidence, then watch the "Seerah" lecture series by Sheikh Yasir Qadhi on YouTube.