This book my sister is reading says there is nothing unique in Christianity. I disagree.
First, there is the concept of grace. Christianity is the only religion which teaches that God's mercy and grace is what saves you. Buddhism is good works and meditation. Hinduism is good works throughout multiple lives. Animists believe there is no life after this so where would you get grace from? Even Judaism, from which Christianity sprang, calls for sacrifices made for forgiveness.
Second, Christianity is the only religion in which one person, who did not deserve it, accepted death in order to atone for other's sins. Christ died for us. He didn't die for himself. He didn't die “for his faith.” He died for us.