When I saw the phrase "2 become 1" as the title of the Marriage programme for a church, 2 things came to mind:
2 people become 1
To become one
They both start with a decision followed by determination, despite the definite challenges that will come, to keep going towards the goal of "Oneness."
For those of us who are married - and hopefully went through pre-marital counselling - the first interpretation is most likely one you heard over and over again. Though I knew it was in the Bible, at first it sounded far-fetched for me - until I started living it.
In fact, it is a continuous process beyond the consumation of a marriage as described by Paul in 1 Cor 6: 15-20. In that pasage, he goes further to advise on what we must avoid in order to glorify God with our bodies - that's another day's story though.
You may have noticed that there are some couples that seem to always (or almost always) be in sync - whether you talk to them together or separately? It is amazing how that oneness occurs but starts with a willingness from both parties to truly become one - as God ordained.
This is not to say that you both will always agree at first or at all but I've found that eventually one person is right. Surrendering to God, who is not the author of confusion, helps a lot too. It gives Him the opportunity to lead us in His way to do His will and accomplish great things to His glory which must be why He borught you and your husband/wife (for our male readers) together. Having the mind of Christ puts us in sync with His will and with each other - and that in itself is a process.
I'm always amazed (& pleased) when my husband says something and I say "that crossed my mind too" or the other way around...it's definitely an easier life - even if it has challenges embedded in what God has laid in your joint-heart.
To become one is the desirable way of life because 2 working in tandem can do more than 1:
...one person chase a thousand of them, and two people put ten thousand to flight...
(Deut 32: 30 - NLT)
"Two people are better off than one, for they can help each other succeed. If one person falls, the other can reach out and help. But someone who falls alone is in real trouble. Likewise, two people lying close together can keep each other warm. But how can one be warm alone? A person standing alone can be attacked and defeated, but two can stand back-to-back and conquer. Three are even better, for a triple-braided cord is not easily broken."
(Ecc 4: 9-12 - NLT)
The only other Person you must allow into your marriage as you 2 become 1 is God...then you're unstoppable because you've got the Power to succeed on your side.