Why do Muslims Pray to Muhammad?
Muslims often claim that Islam is the religion of pure submission to Allah. However, in their daily prayers, Muslims say, "As-salamu alaika ay-yuhan nabiy-yu,” which means, "Peace be upon YOU, O Prophet." Since Muslims are directly addressing Muhammad during their daily prayers, they're assuming that Muhammad can hear them. This requires the divine attribute of omnipresence on Muhammad's part.
Because Muslims speak directly to Muhammad during their daily prayers, they can no longer claim that Islam is the religion of pure submission to Allah. Islam is polytheistic, and any Muslim who prays the way Muhammad commanded is guilty of shirk (associating partners with Allah).
For more on the pagan origins of Islam, watch these videos by David Wood:
"The Truth about the Hajj":
"What Is Islam?":