Instinct for God - from before 'original sin'?

When birds migrate half-way round the world, they know where they are going 'by instinct'. I suppose if any one bird was unfortunate enough to have a more developed brain so that it was aware of other options and choices, this instinct would be drowned. But then it could always just join a flock and follow for the sake of it.

The patterns birds make in the sky when preparing to migrate are hypnotic. They seem to take on a collective mind, and can even appear like a single organism. This picture looks to me like a giant fish in the sky.

But what of mankind? If we have 'original sin' in our make-up, ought there not to be a remnant of even earlier (before the fall) perfect connection with God? A connection that would be truly 'original', although it could not again be wholly innocent or perfect in this world.

This train of thought began with wondering why 'fasting' seems to have no place in the religious tradition I was brought up in. Everything I read about fasting, and its association with prayer, seems to make sense. Not only did Jesus fast for 40 days, but he appears to have taught self-denial (of power, wealth, possessions, etc.) - or at least that all self-centered worldly desires should be secondary to the love of God, and the love of one's neighbour. His example was such: born in a stable with nothing, died on a cross with nothing and lived 'without a place to rest his head'. Where the prosperity gospel comes from, Heaven alone knows!

I was told that fasting can actually bring on a sense of elation - is this true, and why? The one thing I'm sure about is that when my life is busy, busy with 'stuff', and when my mind is a constant buzz of 'interests', even religious 'duties' do not bring me to a frame-shaking sense of His presence. Maybe fasting is a state of mind, uncluttered by the world, where the voice of God can actually be heard.

Before I finally shake off my denominational baggage and head off for a hermit's cave, I suppose I better reflect on the fact that fasting and self-denial was never an end in itself, but a preparation.