Man came about as a result of an accident and exists in an insignificant part of the universe in an insignificant galaxy in an insignificant solar system on a planet that, by chance, just happens to be at about the right distance from the Sun to sustain life.
The Universe that we inhabit, although inevitable, was a happy accident too.
The Drake equation tells us that there is, in all probability, intelligent life in other parts of the universe. There is, in all probability, nothing special or unique about Man. However, due to the vastness of time and space and the limitation of speed, it is highly unlikely that we will ever have any contact with any other intelligence. Therefore, for all intents and purposes, we are alone.
There is nothing in the universe which even hints at a higher force, intelligence or purpose. In fact, the evidence points towards the opposite since it is in a constant state of flux (eg. Super novae, black holes etc). The whole idea is preposterous and even laughable.
In short, we are, effectively, alone and with no global purpose. It is therefore up to each and every one of us to find our own purpose in life because when you are dead, you are dead. So, my friends, enjoy it whilst you can for this is what there is and all there is.