Story about a Japanese high-school boy, who died before his class was summoned to another world

The gods like him, so they made him a fellow god and sent into the summoned class.

He was tasked to work as rescuer , and save the gods devotees.

Because otherworldly people had introduce their Holy church, the actual god of the world was in decline and their devotees were regarded as heretics.

Along the path, he picks up people, especially women's and start his own empire and private harem.