A friend asked me the meaning of nam myoho renge kyo. The literal meaning is something like "Devotion to the Lotus Sutra." However, there is a much deeper meaning. This information comes from Basics of Buddhism (pg 79-83) by Pat Allright printed by SGI.
Myoho = mystic law
Myo is the mystic nature of life and ho is its manifestations
Renge = lotus flower
The lotus flower is special because produces seeds and flowers at the same time. This demonstrates that cause and effect happens at the same time. The lotus blooms and thrives in the mud. Likewise, our Buddha nature can and will thrive even in the midst of less than favorable conditions.
Kyo = teaching
It can also mean sound or the warp of a length of fabric. Buddhist teachings are passed on through past, present, and future. You can definitely notice a difference between chanting silently and chanting out loud.
Nam = devotion, action
Taking the spiritual meaning nam myoho renge kyo means aligning to the mystic law of cause and effect by sound and vibration. When we chant we concentrate with our minds and bodies. We realize that simply by chanting we are changing our life condition. Don't believe me? Try it for yourself. Chant nam myoho renge kyo everyday for 30 days for just 5 minutes. Let me know what you think.