A question that keeps coming up in emerging theology circles - and others I suppose is, 'When did faith become an assent to a set of doctrines?' It's a good question. Can I only be a Christian if I believe certain things? Let's put aside the belief in the centrality of Jesus and the cross, for now - although there are some who don't even see that as necessary. Does it matter whether or not I believe in substitutionary atonement? The virgin birth? The priesthood of all believers? Surely being a Christian isn't a matter of ticking the right boxes on a doctrinal multiple choice paper?
But then, many of these same people to convince you in theological discussion will say, 'it all depends on how you see God. What is your picture of God?' And this is also a good question. Absolutely, how we see God affects our behaviour, our lifestyle, our faith.
But our picture of God depends on our beliefs about God and that comes back to doctrine. So faith IS an assent to certain doctrines - starting with our picture of God - whether we see him as a God of love or punishment or suffering or whatever. Which boxes about God did you tick?
Maybe questions about the virgin birth don't seem so relevent. But ultimately, what you believe about God is going to affect your behaviour, lifestyle etc.
The trouble is that in the past people have simply ticked boxes without applying it to their brains and their lives. They could tick boxes - know what they ought to believe - but not translate it into actual belief and therefore lifestyle change.
Faith is belief (doctrinal assent) that results in relationship with Jesus and a changed lifestyle.