Christian marriage is a covenant relationship

the Hebrew word for covenant is berith, which comes from the root meaning "to cut." A blood covenant was a formal, solemn, and binding agreement—a vow or pledge—between two parties made by "cutting" or dividing of animals into two parts

In Genesis 15:9-10, the blood covenant began with the sacrifice of animals. After splitting them precisely in half, the animal halves were arranged opposite each other on the ground, leaving a pathway between them. The two parties making the covenant would walk from either end of the path, meeting in the middle.            

Family and friends of the bride and groom are seated on opposite sides of the church to symbolize the cutting of the blood covenant. These witnesses are all participants in the wedding covenant

The two individuals meet themselves in the holy ground and  cut the palms of their right hands and then join these hands together as they mutually pledged a vow, promising all of their rights, possessions, and benefits to the other.                                                   Next, the two would exchange their belt and outer coat,

and in so doing, take some part of the other person's name                                The center aisle represents the meeting holy ground, where two lives are joined as one by God. (Exodus 3:5, Matthew 19:6)                                                                            In Bible times, the parents of the bride and groom were ultimately responsible for discerning God's will concerning the choice of a spouse for their children. The wedding tradition of seating the parents in a place of prominence is meant to recognize their responsibility for the couple's union.

Ephesians 5:23-32 reveals that earthly marriages are

a picture of the church's union with Christ.

God initiated the relationship through Christ,

who called and came for his bride, the church.

Christ is the Groom, who established the blood covenant

first initiated by God.

For this reason, the groom enters the church auditorium first