We too often forget that faith is a matter of questioning and struggle before it becomes one of certitude and peace. You have to doubt and reject everything else in order to believe firmly in Christ, and after you have begun to believe, your faith itself must be tested and purified. Christianity is not merely a set of forgone conclusions. Faith tends to be defeated by the burning presence of God in mystery, and seeks refuge from him, flying to comfortable social forms and safe convictions in which purification is no longer an inner battle but a matter of outward gesture.