A rite of passage has three stages. They are separation, transition, and incorporation. Let us look at these stages with respect to a marriage ceremony.
Separation. This process begins long before the ceremony itself. The bride, in particular, tends to be involved deeply in planning the ceremony, thus symbolically separating herself from her old life. Just before the ceremony, she (and the groom) put on special clothes, further separating themselves from their old lives.
Transition. The ceremony itself is the main process of transition. During that time, the bride and groom are separated from the rest of the community (up at the altar). They are given instructions of sorts in that the minister talks about marriage and what is expected of them.
Incorporation. They are brought back into the community as the minister presents them to the community. This process continues with the communal feast in the shape of the reception.