In today's first reading, we hear the second song of the Suffering Servant (Isaiah 49:1-6). In it, the Servant (who will be revealed to be Jesus) tells how God has called him from his mother's womb. God has formed and perfected this Servant for a specific purpose. The Servant knows he has a special purpose and so he is confident in the God who called him to this purpose: "I am made glorious in the sight of the world, and my God is now my strength!"
I think sometimes we drift through life trying to find or create a purpose. We're not sure what life is supposed to be about, so we try to create our own meaning. But real meaning in this life can only come from the one who created this life. To find out what life is about, either in a big picture sense (why are we here) or in a specific sense (what should I do with my life), you have to turn to the Author of Life. And when you turn to God and say, "What the heck is this life about?", he may not tell you immediately. God wants you to walk this path of unknowing with him. He wants you to trust, just like the Suffering Servant trusted.
Halfway through today's reading, the Servant says: "Though I thought I had toiled in vain, and for nothing, uselessly, spent my strength, Yet my reward is with the Lord, my recompense is with my God. All will be made clear in the end, but for now, our part is to turn to the God who made us and to trust him.