One of the biggest philosophical questions in history is whether mankind is intrinsically good or instrinsically bad. I think the question fundamentally misunderstands man as a creation. We are, intrinsically, a reflection of the One who created us. Whenever there is a creator/created relationship, the created must find an identity in it relation to the creator; otherwise its exsistence is senseless. We were created to love God perfectly and to experience the extasy of holiness in that relationship, but the problem is that we live in the inevitability of sin. We are a fallen creation. We wander when left to our own devices, hence one of my favorite lyrics, from the hymn, "Come Thou Fount":

Prone to wander, Lord I feel it
Prone to leave the God I love

When we wander far enough, we leave behind the security of the boundaries God has put in place for us. We even wander far enought to leave behind our true identity (the "True Self" Thomas Merton writes about) as His creation. Life then becomes an endless search for meaning, like a person trying on someone else's clothing to see if anything fits.