The first two steps in the process of becoming a lay disciple of the Buddha are the going for refuge and the undertaking of the five precepts. By the former step a person makes the commitment to accept the Triple Gem—the Buddha, the Dhamma, and the Sangha—as the guiding ideals of his life, by the latter he expresses his determination to bring his actions into harmony with these ideals through right conduct.
Going for Refuge
The Buddha's teaching can be thought of as a kind of building with its own distinct foundation, stories, stairs, and roof. Like any other building the teaching also has a door, and in order to enter it we have to enter through this door. The door of entrance to the teaching of the Buddha is the going for refuge to the Triple Gem — that is, to the Buddha as the fully enlightened teacher, to the Dhamma as the truth taught by him, and to the Sangha as the community of his noble disciples. From ancient times to the present the going for refuge has functioned as the entranceway to the dispensation of the Buddha, giving admission to the rest of the teaching from its lowermost story to its top. All those who embrace the Buddha's teaching do so by passing through the door of taking refuge, while those already committed regularly reaffirm their conviction by making the same threefold profession:
Buddham saranam gacchami
I go for refuge to the Buddha;Dhammam saranam gacchami
I go for refuge to the Dhamma;Sangham saranam gacchami
I go for refuge to the Sangha.
As slight and commonplace as this step might seem, especially in comparison with the lofty achievements lying beyond, its importance should never be underestimated, as it is this act which imparts direction and forward momentum to the entire practice of the Buddhist path.
Taking the Precepts
The path of liberation that the Buddha points to is the threefold training in moral discipline (sila), concentration (samadhi), and wisdom (pañña). These three divisions of the path rise up each in dependence upon its predecessor — concentration upon moral discipline and wisdom upon concentration. The foundation for the entire path, it can be seen, is the training in moral discipline.
The Buddha himself has provided guidelines to developing sila in the form of various sets of precepts. The most basic set of precepts found in the Buddha's teaching is the pañcasila, the five precepts, consisting of the following five training rules:
(1) the training rule of abstaining from taking life;
(2) the training rule of abstaining from taking what is not given;
(3) the training rule of abstaining from sexual misconduct;
(4) the training rule of abstaining from false speech; and
(5) the training rule of abstaining from fermented and distilled intoxicants which are the basis for heedlessness.
These five precepts are the minimal ethical code binding on the Buddhist laity. They are administered regularly by the monks to the lay disciples at almost every service and ceremony, following immediately upon the giving of the three refuges. They are also undertaken afresh each day by earnest lay Buddhists as part of their daily recitation.
The precepts function as the core of the training in moral discipline. They are intended to produce, through methodical practice, that inner purity of will and motivation which comes to expression as virtuous bodily and verbal conduct.
ref.: Going for Refuge & Taking the Precepts by Bhikkhu Bodhi