I think I have read this before. The ending seems familiar, but maybe other stories have similar endings.
The story develops along ordinary lines: God comes back to Earth and enhances life, but challenges ensue. I like the way it is developed. There is some ideological and political theories, that were prevalent, are used to bring the story along. Some of the computer stuff is obviously outdated. I liked the way they traveled between the stars, rather intense and computer heavy, but, hey if you get so far, the rest is not so far out of reach.
The story is that humanity has settled down to just advancing their abilities and taking care of everyone reasonably well. They have ventured out to space, settled the Moon and visited and started studying the moons of Jupiter. They find some artifacts. A spaceship appears with aliens. The aliens happen to have lived on the planet that was between Jupiter and Mars, flew off on a mission to another star and came back. The people they were a part of moved to another planetary system for their own good. Everything is hunky-dory for a while, then a message comes back from the stars about the spaceship. Humanity goes through the back door,so to speak, learns what needs to be done and proceeds to help the aliens make the Universe safe for future generations (which is sort of easy when you are working with Gods), as well as becoming a part of an interstellar community.