2002 Kia Optima Will Not Start

I went to the mall and turned off my car (2002 Kia Optima). When I went to go start it three hours later, it would not start. It was running fine before this incident happened. My dad checked to see if there was any spark coming from the coils, but there was no spark . There is no ignition spark, however the car does turnover. Also, the spark plugs are good and we checked all of the fuses. Do you know what the possible problem could be?