Willpower is an important faculty for human beings to learn. Most of us begin to exert our will fairly early in our development. At about age 2 we begin to exert our will over our environment. Testing our power out on our parents to see who can win in a test of wills. Think 2 year old throwing peas at the mom when it's time to eat, or collapsing in the middle of the store because they want a pack of gum they don't need....
More often than not our parents win because their will (which stems from the 3rd chakra in the gut) is more developed and powerful, and they can more easily push their agenda into the child's energetic and psychological space resulting in their acquiescence.
Whatever the case those early displays of will power and how our parents respond to them set the stage for how we utilize our will later in our lives. If our parents allow us to occasionally exert our will and "win," provided we do so in an appropriate way, then we learn healthy willpower techniques. Conversely, if our parents suppress or overly bend to our will throughout our childhoods then we may learn to either give up too easily or bulldoze over others to get our needs met.
Personal or worldly willpower allows us to achieve goals, influence others and make an impact in the world. Those with developed personal will power often have a healthy sense of self and be able to move through the world believing that if they want or need something they will be able to manifest that without feeling overwhelmed or defeated by obstacles.
We greatly emphasize worldly willpower in the West, as we often teach our children to reach for the stars, achieve and go for what they want. We also tend to over-emphasize competitiveness resulting in a culture obsessed with ensuring their advantage over apparent competitors. An over-developed willpower can result in bullying, callousness and an inability to relax and allow events to unfold naturally when necessary.
Those with an overactive will/gut center (3rd chakra) will often have difficulties accepting reality when it's apparent that surrendering to "the way of it' would be beneficial. Conversely those with an underdeveloped will center often feel like passive victims in the world. They easily lie down and feel as though they cannot manifest positive change for themselves or others.
Spiritual or "Higher" will power differs from worldly willpower in that higher will (which is located in our energy bodies between the 3rd and the 4th chakra centers just between the stomach and the rib cage) pulls the energy of the heart center (compassion, love and empathy) with the powerful force of the gut center (drive, power and confidence) and enables a person to believe that they can seek after the higher aspects of Self without feeling defeated. It also enables a person to manifest personal transformation for themselves or others.
Those with a lot of spiritual willpower will feel moved to passionately seek their own spiritual truth and will actively pursue those activities, people and experiences that will seek to bring them or others spiritual benefit. For many in the west, higher will isn't developed until the transient physical and material success of life begin to fade and become less important in later life. Whereas in many other cultures it is understood that higher will must provide the foundation for worldly will.
Balanced spiritual willpower is in most cases more powerful than worldly willpower because it includes an element of surrender and awareness to the "suchness' of the universe. Additionally those with balanced spiritual willpower understand that there is a time to actively manifest and a time to to surrender and allow. There tends to be greater flow within universal laws or principles (like the laws of karma, the laws of faith, the laws of love, etc...), and a greater practice of empathy, compassion and the integration of wisdom. Spiritual willpower is what allows great souls like Martin Luther King Jr., or Nelson Mandela to not only change the physical world but the hearts of the world as well.
Developing spiritual and worldly willpower are both important. To develop our spiritual willpower we must first be open to a universal reality outside of the physical/material paradigm. We must be willing to submit that our thoughts and energetic output in the world can and will affect the unfoldment of our present reality and as such be willing to adjust those thoughts and emotions to garner our desired results. We must also be willing to listen to our intuition and know when our personal plan interferes with the larger Plan.
We also have to realize that the results may not always be physically tangible but emotional, energetic, spiritual or mental in nature. Although we can use personal willpower and higher will in tandem. For example something like overcoming an addiction is an exercise in higher willpower and personal willpower because it changes our thought streams and behavioral patterns and our physical reality.
Those with undeveloped spiritual willpower may tend to wait for spiritual wisdom to come to them or may be unsure of what spiritual goals would be worthwhile or beneficial for their souls development. Cultivating healthy spiritual willpower can be strengthened by a commitment to discovering our spiritual beliefs, or regular spiritual practice that is in alignment with our deepest selves. Often spiritual willpower and faith are developed in tandem. So as one pursues their Truth, faith is strengthened as well, because the universe (which is really just us) always gives us the experience we need the most.