Jesus the Christ crucified for our sins but raised for our justification is the only means of salvation for us as we put our faith in him. By trusting in God's word of promise Abraham showed the way of salvation centuries before. But faith in God is more basic. By now Peter is instinctively a shepherd, as good as they come. But faith in God is never instinctive and he and Margo and all of us need to be reminded how fragile it is.
Faith is basic at the point of entry to the Christian life.
Only by such confession and belief are we saved. That confession and that faith are great miracles as an unbeliever passes from death to life. But you won't misunderstand me when I say that initial faith is sometimes easier than continuing faith. I love to hear testimony how and why a person initially came to embrace Christ. But I am equally encouraged to hear how and why people continue to believe, especially in the face of suffering.