The purpose of why the Buddhas, the World-Honored Ones. appearing in the world

The Buddhas, the World-Honored Ones, wish to open the door of Buddha wisdom to all living beings, to allow them to attain purity. That is why they appear in the world. They wish to show the Buddha wisdom to living beings, and therefore they appear in the world. They wish to cause living beings to awaken to the Buddha wisdom, and therefore they appear in the world. They wish to induce living beings to enter the path of Buddha wisdom, and therefore they appear in the world. -The Lotus Sutra

Wisdom for Modern Life by Daisaku Ikeda 24/4

We ordinary people do not see that the Buddha exists in own hearts

We ordinary people can see neither our own eyelashes, which are so close, nor the heavens in the distance. Likewise, we do not see that the Buddha exists in our own hearts. -Nichiren

Wisdom for Modern Life by Daisaku Ikeda 21/1

The Buddhas and bodhisattvas of the ten directions and three existences are in you

You must never think that any of the eighty thousand sacred teachings of Shakyamuni Buddha's lifetime or any of the Buddhas and bodhisattvas of the ten directions and three existences are outside yourself. Your practice of the Buddhist teachings will not relieve you of the sufferings of birth and death in the least unless you perceive the true nature of your life. 5/2

The Writings of Nichiren Daishonin
On Attaining Buddhahood in This Lifetime
Written to Toki Jonin in 1255