A: Probably the best way to be assured is through sincere prayer. Ask for God's guidance. Ask for help from the Spirit of Truth in discerning truth from error. Ask for the peace of the Comforter.
Alfred Lord Tennyson wrote that "More things are wrought by prayer than this world dreams of."
If we had visible proof, say in the form of an Adam and Eve who had a personal presence on this world for over 38,000 years, or a Planetary Prince's center for world culture that had been in existence for over 500,000 years, it would be easier to recognize truth from error. But we don't. What we do have is the gift of a logical mind--it's there for a purpose and one of those purposes is to help you sift truth from error, fact from fancy.
As a Urantia Book reader you have not only the best source for factual information relating to the origin, purpose, and destiny of your existence but you also have access to transforming spiritual truths that most people are still searching for. Does your logical mind believe this to be true? If so, what does it matter what those around you, who have less on which to base their beliefs and decisions, think is true? It would be they who are living in a mistaken fantasy. Accept Jesus' exhortation to "fear not!" "