Although loving Hashem is a central Mitzvah, it is significantly more difficult to implement than to recognize its importance. How does one learn to love Hashem? How does one put this into action? How does one develop a love for Hashem?
There are three major approaches suggested to accomplish this goal.
Firstly, there are those who encourage education. Without a clear understanding of what one should love, achieving love is impossible. Therefore both the Rambam (Yisoday HaTorah 1:2) and Rav Hai Gaon (quoted by the Netziv Devorim 6:7) agree that understanding Hashem is a prerequisite to loving Hashem. It is impossible to learn to love something without knowing what it is. However, there is an important difference between the two. According to the Rambam, love is a result of being overwhelmed by His greatness and therefore learning about nature is the best way to facilitate that feeling. By contrast, Rav Hai Gaon believes understanding creation might enable man to be awe-struck, but that is not love. Love comes from learning Torah.
Lastly, the Seforno (Devorim 6:7) writes Be happy doing what is good in His eyes, and realize that there is no greater purpose than that. Presumably his understanding is based on a perceptive psychological insight.
All human desires can fall under two categories; the pursuit of truth and of happiness. The driving force behind all of our decisions is either truth, meaning and purpose or happiness, pleasure and enjoyment. Living a religious life is the best (and only) route to objective purpose and truth and enjoying the ride enables one to quench both thirsts. Synthesizing these two most directly facilitates a love of Hashem. After all, He both authored truth and offered man the opportunity to appreciate it.
Achieving what we want from life by synthesizing truth and happiness, directs us to love Hashem, for he is the root of that achievement.