As the spirit begins to interact with its environment, its knowledge increases. Though still very limited, the spirit is now endowed with the beginnings of its free will, or the ability to choose its actions.  The spirit is tested by various external elements, including those inherent to material life, and is exposed to the influence of less advanced spirits (both incarnate and discarnate) who try to tempt the spirit into wrongdoing and lead it astray.  Such influences are present at every phase of development, though as a spirit progresses, it becomes less vulnerable; God is just, however, and allows spirits, again at all phases, to be aided by the influence of good spirits who encourage them and provide both encouragement and a positive influence.

Free will, then, offers the spirit a chance to resist negative influences and temptations through the good decisions that it makes. Those who choose well take a step forward with each good decision and will advance more quickly than those who choose poorly.