Why go on about belief?

I've been worrying about this a bit lately, and recently I've read several bits of the Bible that make me worry more: why is God so interested in us believing in him?

The usual way we are told you become a Christian is by believing, turning away from everything we do wrong, and giving our lives to God (with Baptism fitting in somewhere in that process).

Fine, but why is believing as important as the others? Surely we don't have any control over what we believe?

Also, isn't it true that what's important about becoming a Christian is that we have a relationship with God, which we are able to do because we have accepted the forgivness he is able to offer us because of the sacrifice that Jesus made.

Now, a good old fashioned literalist evangelical would be able to tell us that it's logically impossible to have a relationship with a god or ask him for forgiveness if we don't believe in him, but I would say that experience often suggests this isn't true - that people with varying degrees of belief in God actually form a relationship with him before they come into a full state of believing in him.

All of this wouldn't be too disturbing if belief were just one of the elements needed to reconcile us with God. But in fact it's more than this - both Jesus (I can't find the reference now - grr) and Paul (Romans 4) appear to refer to the whole process of conversion in a shorthand way by simply calling it "faith" or "belief". The implication is that belief is the most important part of the conversion process.

[Perhaps a counterbalance to these quotes is in Matthew 19 where Jesus tells the rich young man to sell all he has and follow him, rather than believe in him. This implies the relationship stuff I'm keen on.]

Of course, as James (and very often Jesus - see all of Matthew) points out, true faith will lead to putting this stuff into practice. But here again the faith comes first, before being proved by your actions.

This all leads me to ask: what's so great about believing that God saves you because you do it?

And that of course leads me to realise the great mistake I'm making. I want God to be rewarding me (by saving me) for some great work I have done - accepting him into my life and turning away from all I do wrong. But that's not what it's like, is it - I don't get it because I deserve it.

So do I have a point at all? It still makes me very uneasy.

One encouraging thing though: on this issue reading the Bible has genuinely changed my mind: I thought I was pretty sure that the really important thing was asking God's forgiveness and turning to a life following him (and believing was basically a means to that end), but I am now definitely aware that I've got some flaws in my worldview there.

Can anyone shed any light on this?