Nichiren Daishonin states in “Reply to Sairen-bo”:
The votaries of the Lotus Sutra must never discard their faith or cater to the feelings of others. If they devote their lives completely to the Lotus Sutra and follow precisely the golden words of the Buddha, they will, without fail, enjoy a long and healthy life, unaffected by misfortunes and illnesses. They will also achieve the ultimate supreme effect in this present existence and in their future lives.
Furthermore, they will be able to attain the great aspiration of Kosen-rufu.
法华经行者， 若信心不退转， 身无诈亲，其身一切委由法华经，如金言修行者，後世自不待言，今生亦息灾延命，得胜妙之大果报， 必成就广宣流布之大愿也。