The concept of God has numerous variations. Usually God is understood to be the creator of the universe and having attributes such as omnipotence, benevolence, etc. Sometimes God is understood to be humanlike in some ways, though not always. The concept of God has traditionally been the domain of faith based religion. Since God is undoubtedly a supernatural concept, according to the definition of “religion” that this website subscribes to, this means that God must be a religious concept as well.
Some will argue, however, that belief in God does not necessarily require faith. Such people argue that the existence of God can be proven through reason, as opposed to reliance on holy scriptures or prophecy, a belief called Deism.