In line with the bible firstly God created the heavens and the earth on the first day and the second day third day, fourth, fifth and sixth day God made creations now according to the bible text we Christians believe that when God has created everything he saw that he need a ruler of those things so according to bible principles the purpose of man existence is to oversee God's creation because man is a replica of God and the bible signifies man not to only a male but to both genders so man is a significance of God on earth so purpose of man from God's direction from the one creation is to oversee God's works man was created out of God's own image and likeness so that is why we are existing a being a mortal being that can relate with a supernatural being from creation that was the essence of man the essence of man was of creation and that is the purpose to come and oversee the things God created and he saw that they were good according to bible existence.
Books have been written about purpose of man many words have been said by many great people about the existence of man but man in my opinion is a creation to fulfill God's will man purpose is according to God's direction man purpose is not to only make money, man purpose is not to only acquire wealth man purpose is not for fun but man purpose encompasses everything that is of good, build health and otherwise man purpose was to enjoy a fellowship with the creator God needed a being to fellowship so as man missed it.
what we are trying to do now is to see how we can regain that position we had in the father which is the creation.
Man purpose of existence is to fulfill the will of the father so anything we do outside the will of the father then we don't have a purpose because the purpose of the father is why man was created man didn't negotiate his creation we just wake up one day to see ourselves been born without your consent of who your parents are, of were you want to be born into rich or poor,tall black or tall,it is the unpredictable but we see it as a normality that it can occur but man existence is the will of the father so we are supposed to trace the will of the father and dwell and live in the will of the father that is the purpose of existence the purpose of existence is to live for the father every other thing is to aid man's living be it health, wealth is to aid man's living, those are wisdom given to man because we Christians believe man was created in God's image and likeness so man also has a path to play in the creation so every other thing is given by God to man to aid him live that's why you can get rich if you apply the principles not because you are favored if you apply some principles you get rich same principles if you don't if you neglect you get poor so their systems the father created so those systems are to aid us live on earth so the functionality of man is to lean onto the father not outside the father so sickness and other things they are the storms that come in the existence but the purpose of man is to live according to the wills of the father.
We may then ask what is will if the father?
It's simply fellowship with him.
In conclusion of my own opinion of 'Purpose of existence '
is that our primary aim is to function in line with your creator,the function is in diverse ways.