The accumulation of Money is not an end in itself but a means to an end.
The end is the unfoldment of the soul personality to its ideal state and to help other souls unfold, this is the only thing that gives true happiness and not the accumulation of money.
That is why not all rich people are happy, but those who are really happy have found out that it is only by giving and making others happy, can themselves be happy. They understand they are a channel for happiness These ones are already in heaven here and will make heaven in their afterlife.
If you cannot make others happy through your wealth, you are actually poor, not only in spirit but materially because the money will one day dry up because there is no reciprocal return from the Cosmic source that made you a channel and from people whom you didn’t invest in.
Note: This material world we live in is to help us, spirits, to unfold and not to get stuck in the material world.
I love Master Jesus the Christ and I will quote what he said:
“Do not lay up for yourselves treasures on earth, where moth and rust destroy and where thieves break in and steal, but lay up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal. For where your treasure is, there your heart will be also.