Before you get married, you're working mostly on the soulish level (achieving oneness in soul). Then once you say, "I do," you initiate the physical union (achieving oneness in body).

But you still need to continue to nurture one another as you learn how to come together in spiritual agreement (achieving oneness in spirit). In other words, you're working to build a total marriage patterned after God's divine order - spirit, soul, and body:

Spirit - coming together in one spirit.
Soul - having and maintaining mental and emotional oneness.
Body - coming together in the physical union.

After you're married, God still expects you to work on that relationship. God wants you and your mate to experience oneness in every dimension of your relationship, because that's how He sees you once you get married. He no longer sees you as two; He sees you as one (Gen. 2:24; Matt. 19:6).

Oneness Of Spirit Is Vital To A Successful Marriage
In order to build the type of marriage that will bear up under the enemy's attacks, you must develop a oneness of spirit with your mate, because it's only when you're "one" that you can agree successfully in prayer.

For example, if your husband says, "Let's agree that we can do this," and you just give in and say okay, but you don't really want it, that is not agreement. That's called "token manipulation." The minute His plan falls apart, you'll say, "I never wanted it in the first place."

Agreement is when you have discussed the matter, and you both are united in saying, "This is what we will ask and believe God for." Then you will get it every time, because there is tremendous power in agreement (Matt. 18:19).

Now the other side of that is, if you disagree on something, then one of you has to submit in order for the two of you to come into genuine agreement.

Agreement is always the end goal. Without it, it is impossible to have a complete and total marriage.

Source: Marriage and Family by Deborah L. Butler.
Excerpt permission granted by Harrison House Publishers