Oneness, Uniqueness of Allah (Tawheed)

Bukhari :: Book 9 :: Volume 93 :: Hadith 549

Narrated Abu Huraira:

Allah's Apostle said, "Allah guarantees to the person who carries out Jihad for His Cause and nothing compelled him to go out but the Jihad in His Cause, and belief in His Words, that He will either admit him into Paradise or return him with his reward or the booty he has earned to his residence from where he went out." (See Hadith No. 555).