You can be one no matter what your circumstances are. God’s Law is the key.
Being married is a lot like being a citizen of a country. You are under the laws of the civil government. But since this is God’s world and we are all breathing the air He made, whether you believe that or not, we all under His Law. It is His, He made it, and He gets to make the rules. So the civil government can make lots of laws but we are to obey them, “In the Lord.” The same applies to wives; they are to obey their husbands in the Lord.
What does this mean? First of all, obedience does not mean, “work to rule,” which is to drag your feet and only conform to the letter of the law and do it all with a bad attitude. Rather, obedience means to enthusiastically conform yourself to the character of God and to His ministers (people He has placed in authority over you) wherever they are in line with His LawWord.
That brings us to the other crucial thing which is that we must know God’s LawWord so we can discern whether the laws, rules, demands, and regulations given to us are “In the Lord.” To a husband, this will have the effect of having a wife who is an enthusiastically, obedient, dream wife when he asks a godly thing of her and one who is disobedient and impossible to move when he asks her an ungodly thing.
He will then have two choices pressing in on him to choose one or the other.
a) He can bring his character into line with God’s character (as expressed in His LawWord) or
b) He can depart from her and reject God’s character (1 Cor 7:15)
This is the same with every authority relationship we have in life whether in marriage, the church, the state, or otherwise.
In marriage, the husband who chooses a) will be more of a patriarch and blessings will be sure to follow. The husband who choses b) will soon excommunicate himself out of the godly wife’s life and she will be free to marry again, “In the Lord.” He will have proved himself to be no husband, cultivating and protecting all that he was entrusted dominion over, but a tyrant who lives for his own sake and by his own laws rather than for God’s sake and by His Laws.
So the study of God’s LawWord (theonomy) brings progress in sanctification and joy in our Christian lives and in the Kingdom of God. This is why God says over and over again in Scripture that we are to learn, obey, and teach our children God’s laws, statutes, judgments, ordinances, regulations, and rules when we get up, and go to bed, and go in the car, and write little reminders of His law on Post-It Notes on the fridge door, the door-posts, on our wrists and wherever they will be in front of our eyes.