Membership on a piece of paper does not a Christian make.

"Be ye not unequally yoked together with unbelievers"

First, what does it mean to be "yoked together"?

If you have a field in which a herd of oxen are grazing. Some big, some small, some young, some old all mingling in the same field. They ARE NOT YOKED TOGETHER yet they are mingling together.

Yoking two oxen together, is a different matter. There is some kind of harness there that holds them together, and they need to operate together to do what ever they are yoked together to do.

So what would the text mean?
Basically, don't get into the harness (some binding contract that obligates one to accommodate oneself in large measure to another) with an unbeliever, in which you need to "pull together" in one and the same direction.

Mingling, or fellowshiping with unbelievers, etc. is not the same as "yoking oneself together".

Marriage is probably the most all encompassing "yoking together" in a lifetime commitment. When a person decides to spend their life with someone, it's imperative to their happiness that they are on the same page about what's possibly the biggest and most important aspect in their life.
And for a follower of Christ, that encompasses their whole lifestyle. Faith is not just one aspect of their life; it's something that cannot be compartmentalized for the sake of a relationship. It determines how they spend their time, what they enjoy for leisure and entertainment, what they eat, how they dress, how they raise their children, and so many other things!

To be yoked with someone who has taken a lifestyle road that is highly different, as to what is important and what are the goals of life, simply results in a highly stressful relationship not conducive to happiness. Marriage only works when compromise is practiced, but when compromise means giving up that which is the most important (our faith walk with Christ) it is dangerous!!!

Now -- if one finds themselves in an unequal marriage, the Bible recommends staying with the unbelieving spouse, but NOT giving up one's (faith walk with Christ).

So the Biblical recommendation is - do not get into an unequal yoked relationship, avoid it, don't marry thinking you can change the other person and make them more like yourself.

More often than not, it's the believer that compromises and slips into apostasy.
But if you find yourself in an unequal relationship, make God first, and in God's strength be a loving spouse to your mate.

... go to church ...

Marriage is probably the most all encompassing "yoking together" in a lifetime commitment. When a person decides to spend their life with someone, it's imperative to their happiness that they are on the same page about what's possibly the biggest and most important aspect in their life.

Well, the young ladies (and young men) are finding it difficult to find someone as most people don't go to church any more.

What would you say then to them, don't marry and stay single. That's a hard road especially with all the traps that Satan sets up for young people.

Is it ethical to be happy?
Mt 10:34 "Do not think that I came to bring peace on earth. I did not come to bring peace but a sword.

Well, the young ladies (and young men) are finding it difficult to find someone as most people don't go to church any more.

What would you say then to them, don't marry and stay single. That's a hard road especially with all the traps that Satan sets up for young people.

Is it ethical to be happy?
Mt 10:34 "Do not think that I came to bring peace on earth. I did not come to bring peace but a sword.

Send them where they are more likely to meet someone suitable.
Our colleges have been humorously called "marriage markets", and yes, basically it's one of the best places to find someone! (Though, as always when choosing a life partner, great care must be taken for not all who attend our colleges are believers, or suitable marriage partners)

Other places to meet more possible partners are -- camp meetings, youth rallies, maranatha projects, mission projects; anywhere where active believers come together.

It is true that finding someone to whom one is attracted, who is also genuinely committed to Christ, is not an easy task. But it is not impossible.
The person looking, also needs to cultivate and display the characteristics in his/her own life, which they hope to find in another.

If you read chapter nine in "Adventist Home" I don't think you could, in good conscience, tell them to marry an unbeliever. It does seem better to remain single, rather than, in full knowledge, place a lifetime yoke upon themselves with an unbeliever --