The blessings that you, the Honorable Jōren, acquire through your faith in the Lotus Sutra will lend strength to your kind father. Though Devadatta fell into the Avīchi hell, the Buddha predicted that he would in the future become a Buddha named Heavenly King Thus Come One. This was because he belonged to the same extended family as the Buddha. In your case, the relationship is one of father and son. How could the fact that you embrace the Lotus Sutra fail to bring blessing to the departed spirit of your late father?
From Gosho "Letter to Joren-bo" (The Writings of Nichiren Daishonin Volume II, page 572)
From Gosho "Letter to Joren-bo" (The Writings of Nichiren Daishonin Volume II, page 572)
