William James once said, "The best use of life is to spend it for something that outlasts it." The truth is, only the Kingdom of God is going to last. Everything else will eventually vanish. Knowing that, why would you give anything else a higher priority?
Paul said, "My life is worth nothing unless I use it for doing the work assigned me by the Lord Jesus -- the work of telling others the Good News about God’s wonderful kindness and love" (Acts 20:24, LB). If you fail your mission, you’ve wasted the life God gave you. On the other hand, if just one person will be in heaven because of you, your life cannot be considered a failure.
You weren’t placed on earth to do nothing or just live for yourself. God invites you to participate in what he’s doing in the world. Whenever you see God at work, it’s an invitation to join him.