CAA: Christian Anime Alliance

I'm planning to make a story, and want to know how I can make a religion based on Christianity, because I'm basically trying to make a world that's different from ours (Yet, their planet is in the Solar System.) So, based off what I've said, do you think it is better to make a religion based on Christianity or like what??

That depends on the message and the world you're trying to construct. World-building might necessarily include other religions, but if you're going to do something based on Christianity, I would (personally, my own opinion) make certain it doesn't violate core beliefs about Christ that might lead a less-informed reader in the wrong direction. If you've never read C.S. Lewis' Space Trilogy (starting with "Out of the Silent Planet"), you might want to do so to get an idea of how he dealt with the concept of Christianity on other planets.

I second checking up on C.S. Lewis’ works. He has a beautiful way of marrying Christian faith and fiction in his stories.