Though we speak of observing the Ten Worlds in one’s own life as an ordinary person, the key issue is whether we can manifest the world of Buddhahood. The reason the Daishonin talks about “perceiving the Ten Worlds” and not “perceiving the world of Buddhahood” is that even when the world of Buddhahood manifests, the other nine worlds don’t simply disappear. That’s because “observing the mind” always means observing the true aspect of the mutual possession of the Ten Worlds.
For instance, suppose you were to reach a complete impasse, agonizing in the life-state of the world of Hell. By perceiving the true aspect of the mutual possession of the Ten Worlds and being convinced of the great life force of the world of Buddhahood that undeniably endows your life, you can overcome everything and realize victory.

​​This guidance is an abstract from 'The World of Nichiren Daishonin Writings' with universal value and application​

Steadfast dedication to the way of the oneness of mentor and disciple is the key to our own and everyone’s happiness. The Lotus Sutra explains this truth as the pledge to “make all persons equal to me, without any distinction between us” (LS2, 36).7 This is the paean of a champion of humanity. It declares: “I am a human being. You, too, are human beings. How great human beings are!” This is the heart of the Lotus Sutra.

​​This guidance is an abstract from 'The World of Nichiren Daishonin Writings' with universal value and application​

The ultimate Law of the universe and the life of the Thus Come One that is one with this Law are at the core of the Buddha’s spirit and actions. This includes profound insight into and empathy with life and the resulting compassion toward all living beings, willingness to share the suffering of human beings, and actions infused with wisdom and the aspiration to save the suffering. The Daishonin realized that this supreme Law is Nam-myoho-renge-kyo, which he describes as his “life.”
The Daishonin revealed Nam-myoho-renge-kyo as the fundamental object of devotion for people of the Latter Day of the Law. What results from this understanding is a thoroughly humanistic religion.

​​This guidance is an abstract from 'The World of Nichiren Daishonin Writings' with universal value and application​

The term honzon, or object of devotion, means that which is respected or revered as fundamental. The Daishonin manifested the Gohonzon as the object worthy of supreme respect that all people should take as a fundamental standard.
In praying to the Gohonzon, the awareness that it is a graphic expression of Nam-myoho- renge-kyo, the very life of Nichiren Daishonin, is the key. As the Daishonin states, “I, Nichiren, have inscribed my life. . . . The soul of Nichiren is nothing other than Nam-myoho-renge-kyo” (The Writings of Nichiren Daishonin, p. 412). The Daishonin manifested the supremely noble entity in his own life that is the foundation of life, the object of utmost veneration. At the same time, he recognized that the same supremely noble entity exists in the lives of all people. 

​​This guidance is an abstract from 'The World of Nichiren Daishonin Writings' with universal value and application​