Last Cathedral

Year 3200...
Humans have progressed so much that they have been able to conquer space...
But there are still many disagreements between groups of people, so interstellar civilizations have emerged from different viewpoints , ideologies and even old and new religions.
Among them all, a group of religious people have created a civilization based on Christianity to preserve their religion until the advent of Christ...
But they are always threatened by other civilizations, so they try to defend the last interstellar cathedral that is sacred to them, so that it will not be harmed in the midst of various wars...