Where is gateway church? Robert Morris. Gateway Church is a non-denominational, charismatic Christian multi-site megachurch based in Southlake, Texas, near Fort Worth.What is a gateway church? The Gateway Church is a welcoming multi-cultural charismatic Church in King’s Lynn. We are made up of young and old people from all walks of life and 34 different nations.What is the gateway church? The Gateway Church is a vibrant faith community centered in and committed to the city of Des Moines.