We are not wise enough, pure enough, or strong enough to aim and sustain such a single motive over a lifetime. That way lies fanaticism or failure. But if the single motive is the master motivation of God's calling, the answer is yes. In any and all situations, both today and tomorrow's tomorrow, God's call to us is the unchanging and ultimate whence, what, why, and whither of our lives. Calling is a 'yes' to God that carries a 'no' to the chaos of modern demands. Calling is the key to tracing the story line of our lives and unriddling the meaning of our existence in a chaotic world.
Os Guinness, The Call: Finding and Fulfilling the Central Purpose of Your Life
calling, motivation, purpose