The Jason and the Argo by Dorothy Olson

A luxury liner sets off on a three-year voyage to a vacation moon when they are beset by a solar storm which throws them off course. They are surprised to find an alien ship lost as they are. The aliens, known as Tralians have superior technological and inform the humans that the only way to survive is to join ships and try to make planet-fall. They locate a likely planet and the joined ships make a successful landing. In exploring their new home they discover the indigenous life forms consist of plant-like forms that open up communication with the earthlings and Tralians. The tree-forms are very spiritual and are very glad to have the visitors who bring animal life forms which can provide many things that have been previously lacking almost as if places had been prepared for them by the creator. The Trailians start acting very secretive and head off to their own home in the mountains leaving the humans to form a government and start production of food and products. Eventually it is discovered that a previous ship of Trailians had also landed there and had built a nuclear reactor which was now causing the trees in the area to behave erratically. The previous Trailians had been asked to leave. The current Tralians have figured this out and have seperated themselves from the humans so as not to taint them. They are very much in love with both the humans and the planet and wish to stay. The humans have brought their religions along, chief among them is the story of Jesus and his coming to earth to forgive our sins. Working side by side with the humans the Trailians are able to fix the reactor and return the planet to its pristine state. The indigenous plant life is so grateful they allow the Trailians to stay this time. The Trailians now understand Jesus message and the meaning of redemption.