The journey McCarthy's characters find themselves on deals with truth throughout the novel. Rather than finding one place that is safe, staying there and trying to survive, they are on a dangerous and long journey with uncertain odds for their future. Is the world dead? Are there still humans who exist that are not criminals, murderers and cannibals? All hope the man and his son have for a future is based on finding the answer to those questions.
Trust is another theme entirely, and McCarthy has created a setting where it is almost impossible to trust. Only the relationship between father and son ca be called something resembling trust. They encounter others who mean them no harm, but in now way could the reader argue they are trusting. Only by forsaking trust have they managed to survive thus far.