Can a layperson cultivate to the level of a fourth-fruit arhat?

Answer: First of all, a person who has completely eliminated innate self-grasping is, in the Small Vehicle, an arhat of the fourth fruit, and in the Great Vehicle, an eighth-bhūmi bodhisattva. A layperson cannot possibly cultivate to the fourth fruit of arhatship; the highest a layperson can reach is the third fruit, and reaching the third fruit is extremely difficult. A person of the third fruit is almost entirely uninterested in worldly dharmas in secular life and will certainly find a way to leave home; moreover, the opportunities for leaving home are very numerous, and such a person has even less interest in family. If they do not leave home, most simply live out their days according to conditions, but there still remain some attachments not yet eliminated; regarding household life and work, they go along with conditions, without strong attachment.

As for the Great Vehicle's fourth-fruit arhats, they are at the eighth-bhūmi bodhisattva stage, and they generally do not come to the Sahā world. Even if they come to this world, they would not live a secular household life, such as working to support a family—that is utterly impossible. Their merit is immensely vast; how could they stoop to such a lowly thing as doing secular work to get by? Their work of saving sentient beings follows conditions, without a trace of attachment, so why would they lower themselves to work and support a family? In fact, even finding a first-bhūmi bodhisattva or a person of the third fruit in the Sahā world is extremely rare. Bodhisattvas on the bhūmis generally do not remain householders; they all leave home to save sentient beings—unless there are so many bodhisattvas that not all of them need to leave home to serve as models for sentient beings.