Our self-interest may in fact be the perfect thing to lead us to God-interest, as we will nearly always choose what we believe is best for ourselves. And God is good and so gracious and so loving that, well, He is good for us.
But choosing God is not enough.
When we choose God, what we're saying is that we want God. There's something in Him or something about Him that satisfies some kind of need that we have. And it is this that we really want; it just so happens that we find it in God. The truth is that most of us would take it anywhere if we could find it, so just starting out, God is a bit of a neutral party.
Wanting God is good, and it does lead us toward God-interest, but it is a far cry from actually loving God, which is the ultimate aim.
Wanting God can never get us to the kind of relationship with God that He desires. Nor can it get us to a relationship with Him that satisfies our souls. It's this truth that makes faith a little more difficult than just the notion of self-interest or God-interest; it requires something else.
Faith requires that we have a bit of humility. Namely, that we are able to break out of our own perspective and stop thinking about our own satisfaction for a minute. It requires that we learn what is good because of our own intense desire for good things, but then that we take what we know about goodness and pursue it on its own merits. To say it another way, we come to God through our self-interest because what He offers is good for us, but if we can embrace humility and grow in faith, we come to a place where we want God because He is good.
This is the turning point. If we can step outside of ourselves and realize that God is good not just because He is good to us, but because He is thoroughly good in His own nature, then this is the first step toward truly loving Him. Once we realize He is simply good, we start to see all of the other things about Him that He wants us to know - things that our life experience may not have taught us yet.
You don't know God as Provider until you find yourself in need. You don't know God as Healer until you're broken. You don't know God as merciful until you find yourself in need of mercy. But when you humble yourself and recognize His goodness, you start to learn these things about Him before you even need to know them. Because your faith starts to become centered on who He is and not on what you need (or want). And the more you're focused on who He is, the more you see of Him. The more you see of Him, the more you just can't help but love Him.
Not because of who He is for you, but just because of who He is.
So yes, our self-interest can lead us to God-interest, but God-interest can only take us so far if we remain solely (or even primarily) self-interested. True faith requires something more. And that, ironically (or not so much), circles us right back to where we were last week - surrender.