Deep inside there could be this feeling that money (or success) could change us into people we don't want to be. We will not then be nice people, struggling people, people who others can pity (or admire), people who are brave and courageous in the face of odds and people who are classic victims. All these are things that keep us rooted to that 'nice' image we have. But poor.
Now if the thought is that money or success might change us, and we are not acting in a manner that is conducive for money or success to flow in, all we need to see is what we are scared of becoming. Will money make us arrogant, conceited, loud, thoughtless, proud, cruel and whatever else we are scared of becoming?
The best way then is to first be fine with all those traits in us. Instead of holding out against them, if we accept that we ave all those characteristics in us, and we show a bit of that characteristic too, we will actually be telling the Universe we are being more honest with it, with ourselves. A bit of ugliness is OK, as long as it is ours. Be it, show it. It makes me more authentic, more honest. A little less 'good' but more 'me' and more 'honest me'.
I think it is also easier then to be ourselves when we get the money or success. The key then seems to be not that we are scared that money will change us, but that we are cared that money will show us for what we really are. And if we are OK with that, then there is nothing to fear. Let it come right in!