this psalm is like a shout out to the world – to those who are rich and those who are poor – with the major theme being the question of where you put your trust. the psalmist suggests that putting your truth in your wealth is not a sign of wisdom:
‘Why should I fear when evil days come, when wicked deceivers surround me — those who trust in their wealth and boast of their great riches?’ [5,6]
‘For all can see that the wise die, that the foolish and the senseless also perish, leaving their wealth to others’ 
‘People, despite their wealth, do not endure; they are like the beasts that perish.’ 
‘This is the fate of those who trust in themselves, and of their followers, who approve their sayings. They are like sheep and are destined to die; death will be their shepherd (but the upright will prevail over them in the morning). Their forms will decay in the grave, far from their princely mansions.’ [13,14]
‘People who have wealth but lack understanding are like the beasts that perish.’ 
Kind of a, “Yes, you have money now, but one day you will die [like everyone else] and then what good will your money have done you?
A warning to those who are rich to make sure that life goes beyond their riches – that the ‘life to the full’ they may feel like they are living now also extends into an everlasting life to the full.
And a warning or maybe comforting reminder to those who are not rich to not get caught up in envying those who are or distracted by the wealth of others but to focus on living well here and also take heart in the fact that we do look to life beyond this one.
‘But God will redeem me from the realm of the dead; He will surely take me to himself.’