In all cases, whether alone or with a group, whether as a householder or home-leaver, it is better to practice under a qualified master. Practice without the guidance of a master will probably not be too fruitful. Practicing with a master can save you time. A master's understanding and experience can help you firmly grasp the essentials of practice and cultivate a correct view of Buddhadharma. This enables you to more quickly free yourself from the vexations of body and mind. With a master, time otherwise spent studying sutras and worrying about following the right path, can be devoted single-mindedly to practice.

There are people, however, whose karmic roots are sharp and deep; that is, they have practiced well for many lifetimes. Such people will make speedy progress whether they have the guidance of a master or not. They will understand Buddhadharma and will not stray from the path. For example, Sakyamuni practiced with many masters before becoming completely enlightened, but, as he was not satisfied with their teachings, he practiced on his own for six years. He did not attain enlightenment until he put down everything. Sakyamuni did have teachers, but his was a case of self-enlightenment. The Sixth Patriarch, Hui-neng (638-713), also got enlightened without the guidance of a master. In his case, hearing one line of the Diamond Sutra was enough. Later, the Fifth Patriarch confirmed his attainment. In essence, the Diamond Sutra was his teacher.

As you can see, such people are rare. Unless practitioners feel they are on a par with people such as the Buddha and the Sixth Patriarch, I would suggest that they seek the guidance of a good master. If practitioners have mental obstructions or difficulty with their practice, masters can help them resolve their problems. Also, if practitioners have some type of experience, a master can determine whether it is genuine or not. Left alone, practitioners may deceive themselves, thinking that an illusory experience is enlightenment. That would be harmful to their practice.