God is the unknown in our past, present and future.  What we don't currently understand about the universe is most often explained by god.  In the past god answered such questions as why does the sun rise every day? or where does lightning come from?  Now it mainly answers the bigger questions (since science has explained the previously mysterious phenomenon) like what created the universe? or how did life arise?  Projected into the future, god becomes infinite (possibly from our inability to grasp such a concept).  A religious understanding of god usually comes conveniently equipped with supposed knowledge of what happens to us after death (heaven/hell, reincarnation, purgatory, moksha).  In the present questions concerning suffering or morality get answers concerning a higher power (or evolution, another example of science explaining away god).