Did Billy Graham do anything illegal? Did he invest his income over time into a home, stock market, etc. Anyone can be a millionaire in America. If you make minimum wage and save 10% of your income, invest it wisely, you can be a millionaire by the time you retire. HOWEVER you have to wisely withdraw the money in order to make it last during your retired years.
If all Billy Graham did was preach the gospel, he wasn't rich when he started out, this came over time and over years of getting donations. What is wrong with that. If you took every penny from every millionaire in the world and spread the wealth so as everyone would get the same portion, in 6 months economists have said (without government interference of course) the money would be right back into the same hands that started it. Also, if our government took every penny from every billionaire and millionaire in America, it would only cover the national budget for about 3 months.
Billy Graham also gave tithes of his own income 10% to getting churches started, helping hospitals, etc. Finding fault with what someone owns, such as Musk, Bezos, or even ministers, is greed and envy on your part. This is why some people are poor, greed and envy, instead of hard work and wise spending.
Remember the parable of the 3 men, one had 10 portions, one 5, and one 1. The 10 and 5 invested wisely and grew their investment, the guy with 1, burried his and it was taken from him and given to the one who had 10. Not what you have, but what your heart has, and what you do with what you have. Sure, you are supposed to help others, but that is from your heart as well as your bank account, not because you think someone is richer and should give theirs. Who cares, it is what you do with yours and your heart.