Abusive and fanatical, Nathan Price is a Baptist minister who lives unswervingly by his own rigid and simplistic moral code. As a soldier during World War II, Nathan escaped the Battaan Death March, and the almost certain death it brought with it, by sheer chance. Because he escaped the fate of the rest of his battalion he views himself as a coward, despised by God. He vows never to be a coward again, by which he means he will never again leave a dangerous situation behind. He devotes his life to saving as many souls as he can, through his missionary work.
As becomes increasingly clear as the novel progresses, Nathan is not brave but cowardly, and not a man selflessly devoted to a cause but a man devoted to nothing and no one but himself. It is his cowardice that drives him to adopt his rigid and simplistic moral code in the first place. He is unable to face the messy and unjust reality of life. He convinces himself that there is a deity who cleanly and sharply rewards all good and punishes all bad. Not only is he craven and self-deluding, Nathan is also an egomaniac of the highest order. His attempt to save unenlightened souls has nothing to do with the well being of those particular souls. Instead this activity, like all others that he undertakes, has as its only goal the well being of his own soul. He is so obsessed with securing his own personal ticket to salvation that he knowingly imperils the lives of his wife and daughters. He is unable to look outside of his own need even for their sakes.
Actually, it seems that Nathan not only lacks the appropriate level of concern and compassion for his family, but that he positively resents them. Nathan is, first of all, a rabid male chauvinist who dismisses the very possibility of female intelligence. However, his complex relationship to his family does not derive from anything so simple as mere sexism. Convinced that God is constantly watching and judging him, and that God disapproves of all activity not devoted to spreading His name, Nathan is enraged by his own sexual urges. Instead of turning his rage on himself, however, he conveniently turns his rage on his beautiful wife for tempting him, and on his daughters for being the physical manifestations of his lapses in will power. His abusive behavior toward them, including his endangerment of their lives, can be seen as a form of revenge on those who would make him something other than he wants to be.