At TimeOut (when our evening service looks at a big topic), we looked at how the book of Ecclesiastes considers the big question of purpose in existence. The Preacher at the centre of the book asks the question - what if this is all that there is? I've loved this book of the Bible as I have studied it - it has been the most intellectually challenging thing I have read in a long time and it is wonderfully encouraging.
If you want to hear more about this the following resources might be useful:
The song by Thrice - Window
The excellent book, "Why everything matters" by Philip Ryken. There is also a series of talks by him downloadable if you click here.
You could listen to the song by Thrice - "Window"
Finally you could listen to my talk here.