"'Hell Is the Land of Tranquil Light': 'When he was alive, he was a Buddha in life, and now he is a Buddha in death. He is a Buddha in both life and death. This is what is meant by that most important doctrine called attaining Buddhahood in one’s present form. The fourth volume of the Lotus Sutra states, "If one can uphold this [sutra], one will be upholding the Buddha’s body" [LSOC11, 220]' (WND-1, 456).
“This passage is from a letter that Nichiren Daishonin wrote to the lay nun Ueno, the mother of Nanjo Tokimitsu, known as ‘Ueno the Worthy,’ and the wife of Nanjo Hyoe Shichiro. After her husband died, the lay nun Ueno splendidly raised their nine children and remained pure-hearted in her faith.
“Here, the Daishonin says that when her husband, Nanjo Hyoe Shichiro, was alive, he was a ‘Buddha in life,’ and now, after his death, he is a ‘Buddha in death.’ He was a Buddha in both life and death, the Daishonin writes.
“Why? Because all of us, who have appeared in this world to carry out kosen-rufu, are the true disciples of Nichiren Daishonin, the Buddha of the Latter Day of the Law, and courageous Bodhisattvas of the Earth. The fact that we have made the same great vow as the Daishonin to propagate the Lotus Sutra and are striving for kosen-rufu for the happiness of others is proof that we ourselves are Buddhas and Bodhisattvas of the Earth. That is because only Buddhas and the Bodhisattvas of the Earth can carry out the sacred work of kosen-rufu.
“To find utmost enjoyment in Soka Gakkai activities, in sharing this Buddhism with others, and in chanting Nam-myoho-renge-kyo; to brim with enthusiasm for taking on new challenges, and to feel that life itself is joy—this is the life-state of Buddhahood, of being a ‘Buddha in life.’"
SGI Newsletter No. 8707, The New Human Revolution––Vol. 26: Chap. 1, Atsuta 42,translated 21st Jan. 2013