Opportunity could be defined in so many ways. There's one way of defining it, equality of opportunity, which is in fact the equality of capability, but the libertarians got there first and they have - like the Americans getting onto the moon, naming every crater after something like an astronaut - they have got there and named "opportunity" in a way that we cannot get ownership of now.
We look upon prayer simply as a means of getting things for ourselves, but the biblical purpose of prayer is that we may get to know God Himself.