What started as a game of hide and seek ended in the adventure of a lifetime! Corky, Angie and Justin were playing a rousing game when a storm forced them to look for shelter - leading them to a strange house in the woods. Inside, they found the solar iron robot SIR and Professor Bumble; and after a failed experiment, the gang found themselves... somewhere, and sometime else. With no idea how to get home, the Flying House and its inhabitants travel throughout time, inadvertently experiencing the events of the Bible's New Testament along the way. Can the children find their way home?
While playing a video game one day, Tomoru, Dai and Mio found themselves accidentally transported inside yet another game: Eureka, designed by the studious Dr Galileo! In order to return to the real world, the gang must earn ten Eureka stones by completing various scientific challenges - but they have competition. Fellow rivals Yukio, Suzuka, and Kouta, along with Dr Galileo's rival Dr Galilei, are also trying to find the stones. From collecting fossils to stopping lightning in the sky, thrilling scientific challenges await!
First off, Flying House is 100% aimed at Bible stories, and Sounanda is not. Regardless, I think if you enjoyed the non-religious elements of Flying House, you'd enjoy Sounanda too. Children are pulled into a strange new world or story in each anime, and they in general have a similar feel. Perhaps you could think of Sounanda as being Flying House's alter-ego; while Flying House is focused on religion, Sounanda is focused on science.
Chris and Joy were two normal children living normal lives - until one day they discovered a magical bible called the Superbook. When everyday events touch upon a holy story, the Superbook glows, opens, and transports the children and their toy robot back into time to experience an event for themselves. Whether it's witnessing the creation of Noah's Ark, discovering the origin of Mother's Day, or coming face to face with David and Goliath, there are plenty of stories the children will experience together.
It's flat out impossible to recommend a better pair of anime for each other, given that they are sister series of sorts. Both Flying House and Superbook are filled with Christianity galore and follow a group of children + robot in their adventures through stories of the Bible.