Islam.... Why?
1. Because Islam is the religion chosen by Allah for all humanity.
2. Because Islam is the religion of all prophets since Adam to Mohammad (Peace be upon them all).
3. Because Islam is the religion delivered by all Messengers of Allah and Islam is the seal of all heavenly revelations, and
4. Because Prophet Muhammad -- Sallallahu alayhi wasallam -- the Messenger of Islam is the last of God's apostles, and
5. Because The Qur'an is the last of Allah's scriptures.
6. Allah ta'ala (Glory be to Him) says: "Do they seek other than the Deen (Religion) of Allah? While all creatures in the heavens and on earth have, Willingly or unwillingly, bowed to His Will (accepted Islam), and to Him shall they All be brought back," (The Qur'an 3:83) "If anyone desires a Deen (Religion) other than Islam (submission to Allah) it will never be accepted from him; and in the Hereafter he will be in the ranks of those who have lost (everything) (The Qur'an 3:85).