He himself acts righteously, and He demands that His people do the same. This is the consistent teaching of the Old Testament. It is a Stable Fellowship. The concept of fellowship with God based on a legal covenant meant that there was a stable and dependable element in the religion of the Old Testament. The advantages of having marriage based on a legal contract with sacred guarantees are plain to see.
Marriage has to be based on something more than fluctuating human emotions.
We must also appreciate that a believer's union and fellowship with God rest on something more durable and stable than the actual experience of the believer in the fellowship. The covenant spells out the terms and conditions of the relationship. The covenant partner may know where he stands. He knows his rights and titles as well as his obligations and responsibilities. This means that the fellowship in the partnership is both dependable and predictable.