Stranger In A Strange Land by Robert A. Heinlein
Hugo Award winner
This is the story of Valentine Michael Smith, who was raised as a child by Martians after disaster struck the first human mission to Mars. When humans return to Mars, they bring him back with them. However, he perceives and understands things differently than Earthlings; and he is unfamiliar with the ways of the world on Earth.
He has no family on Earth. But as lone survivor of the Mars crew he is legally entitled to great wealth and is the official representative of Mars. Initially, the government tries to isolate and control him. A sympathetic nurse helps him escape. He is taken under the wing by Jubal Harshaw, an affluent nonconformist writer.
Harshaw introduces Michael to various aspects of life and presents him with a different point of view than is the norm. Michael's perceptions are those of a true outsider. He faces the issues of a person with one foot on each of two separate worlds. We see society without its common assumptions.
Eventually, he evolves into a quasi-religious leader advocating a mix of his Martian culture / mental practices and Harshaw's philosophy. This puts him at odds with the status quo and its representatives (religious and government forces).
There are good reasons why it won its awards, but it is also a book of its time (1961) and will probably not be as wildly captivating to new readers today as it was in the 1960s and 1970s. Some of its social criticism is less controversial today, but some attitudes are now outdated, even offensively so.
Those who read the book in the 1960s or 1970s may be interested to know that there is now an "uncut" edition available. This includes material that was originally excluded as too sensational or risky.