I agree with what Dave Ramsey said that there's always a difference between generosity and just hoarding your money. It's also up to luck because you can never control what would happen to you, but I guess it's good karma. No matter what you believe in, it's always going to be a positive impact if you were to give out your blessings.
A personal view on it, I would like to be more generous and then prosper the right way. Not that because I have money, then I'm already prosperous. It's not always like that. If you are happy, you will be able to be successful because you have helped someone.
There is a proverb that states “It is not what you know. It is who you know” and I think this is an example of what you mention, being known as a generous person opens many doors and it get you to approach people that otherwise would have been inaccessible for you, this helps you to create a wide social network which is invaluable if you want to achieve success, so even if you need some money to do that the money spent is nothing compared to what you can get out of it.