“What did the apostolic writers have in mind when they spoke of faith? Nothing less than what they took to be the distinctive essence of Christianity: namely, a belief-and-behavior commitment to Jesus Christ, the divine-human Lord, who came to earth, died for sins, rose from death, returned to heaven, reigns now over the cosmos as his Father’s nominated vice-regent, and will reappear to judge everyone and to take his own people into glory, where they will be with him in unimaginable joy forever. This was ‘the faith’ that was taught and defended against Gnostic syncretists from the start (we see Paul in Colossians and John in his letters actually doing that); soon it was enshrined in creeds, which began as syllabi for catechetical instruction of enquirers; and, with its Trinitarian implications made explicit, it has since then been at the heart of mainstream Christianity everywhere. …
So faith, that is, believing, is in the New Testament a ‘two-tone’ reality, a response to God’s self-revelation in Christ that is both intellectual and relational. Mere credence—assent, that is, to ‘the faith’—is not faith, nor is commitment to a God or a Christ who is merely a product of human imagination.”
view an excerpt here.