Anders - Sikhism's concept of God is unique, whereas in Judaism and Christianity [possibly Islam also] one jealous God is focussed on, Sikhism says there is one God, full stop [whereas in other religions there is one God that is seen as higher than other Gods, for example, Allah was originally a tribal God that was elevated to tawheedic status].
The God portrayed in Sikhism is not a God coming from a pantheon of God which once was portrayed in form and then elevated - he/she/it was always formless!
Sikhs hold the view that Allah, Jesus, Shiva, Ram, Krishna, Vishnu, Ha'Shem, Jehovah and many others are just names of Waheguru.
Some Sikhs will say that minor dieties [Pagan Gods, Hindu Gods] are creations of Waheguru but some will deny their existence altogether.
~CaramelChocolate~