The concept of God in Sikhism is uncompromisingly monotheistic, as symbolized by "Ik Onkar" (one God), a central tenet of Sikh philosophy. The fundamental belief of Sikhism is that God exists, indescribable yet knowable and perceivable to anyone who is prepared to dedicate the time and energy to become perceptive to their persona.
wow. sri guru granth sahib ji is 1,430 pages of poems and hymns praising one all knowing god, Ik Onkar. sikhs believe we all believe in the same god, we just call him different names.