I believe that, as Christians, the purpose of our lives is to glorify God. I read this study on 'Giving Glory to God' by Andrew Berhardt - http://dtjsoft.com/giving-glory-to-god/ (please read it) - and it was very eye opening and made me realise that my life is not actually my own and I should live to glorify God in everything I do. But first and foremost, we all, including myself, need to really develop a love and appreciation for God, because then, as the study also says, we will have the desire created in us to bring as much glory to Him as we possibly can. Without love, it's all in vain.
This is a section of the study text about our role of stewardship
What do we think of when we hear the word 'stewardship'? Tithing?
That's what I thought it meant until I learned its true meaning from J.R.R. Tolkien's Return Of The King, the final part of the Lord Of The Rings trilogy. In the book, the country of Gondor had been without a true king for a thousand years, but it was ruled by stewards who were to govern Gondor until one who could rightfully claim the throne returned. When the king finally did return, the last steward did not want to give up his position but thought that he deserved to rule on the throne himself. His pride had caused him to forget where his authority came from.
A steward is a manager of someone else's property. No matter how much time elapses, a steward must take care of the property given to him, and always be ready to return it to the owner when asked.
God owns more than our money. He owns all of our material possessions. He owns the whole world (hence the first commission God gave to man - to take care of the earth). And He owns us. We are only stewards of what God has given us. At the final judgement, we believers will not be judged on what we did for ourselves but what we did for Jesus Christ. We will have to give an accounting for what we did with what God gave us.
In Mark 12, some of the Pharisees tried to trap Jesus with a question about taxes.
And they come and say to him, Teacher, we know that you are true, and care not for anyone; for you regard not the men's person, but teach the way of God with truth: Is it lawful to give tribute to Caesar or not? Should we give tribute or should we not give? ...
- Mark 12:14,15
Jesus knew they asked the question to trap him. However, He didn't just answer the question with a yes or no answer...
...Why do you tempt me? Bring me a denarius that I may see it. And they brought it. And he says to them, Whose is this image and superscription? And they said to him, Caesar's. And Jesus answering said to them, Pay what is Caesar's to Caesar, and what is God's to God. And they wondered at him.
- Mark 12:15-17
The Pharisees' question dealt only with rendering what was due to Caesar, but Jesus' reply lead them to a much more important issue - our stewardship of what God has given us. Just as the coin belonged to Caesar because Caesar's image was on it, so we belong to God because we were created in His image.
Think of yourself as a steward of God's image. The image is not yours. What you do with your life will either tarnish God's image or glorify it.