Final answer:
The "first step" to living life to your full potential according to Osteen is believing in yourself, which enables you to set and pursue your career goals with optimism and determination.
Step-by-step explanation:
According to Osteen, the "first step" to living life to your full potential is b) Believing in yourself. This belief is fundamental to starting ambitious long-term undertakings, as given in the reference information which states that one has to believe in what is possible to get started. It's about stepping beyond limiting beliefs that could be holding you back from achieving your career goals and embracing a mindset that allows for growth, adaptability, and optimism in your professional journey.
Believing in yourself is crucial for setting career goals, staying motivated, and taking the necessary action steps to achieve them. A positive attitude and self-belief are essential in overcoming obstacles and realizing your full potential. It enables individuals to remain optimistic and take persistent action towards their goals, even in the face of challenges.