A reader writes to ask:

I’m almost 29, married, have two kids, and am a convert to Orthodox Christianity. I consider myself pretty devout, am well educated (AB in philosophy from a prestigious liberal arts university), and firmly adhere to the Church’s teaching on the body, sexuality, and marriage (my wife and I are big fans of the Catholic Church’s theology of the body, Humanae Vitae, etc., and are well-versed in those terms and arguments).

My youngest sister is almost 23 and just graduated from a Jesuit university with a theater degree. She recently decided to move into an apartment with her boyfriend. She’s somewhat antipathetic towards “organized religion,” though she prays regularly – something she claims validated her decision to move in with her boyfriend.

We were both raised in a mainline protestant church and were regularly involved in church growing up. Our parents are still together. They raised us well and taught us the faith from day one, if not always in the most thoughtful or deepest of ways. That’s to say, we were definitely raised Christian, taught right from wrong, and (as is relevant here) taught that sex is for marriage. But the version of Christianity I mostly recall hearing growing up could be summarized, “God sent Jesus to earth to teach us about him and show us how to live a good life and love each other and died on the cross to save us from our sins and if we believe in him and try to live a good life like he taught, then we can live forever with God in heaven.” It’s not technically wrong, but most can see there is a lot lacking.

All that’s to preface and explain this oddity: despite a common Christian upbringing in a stable and loving home, and only six years between us in age, my sister and I have fallen firmly on the opposite sides of the millennial divide – me strongly religious, and her thoroughly (if unwittingly) in the Moral Therapeutic Deism camp.

So my question is: how am I supposed to talk to my sister about human sexuality, marriage, and the faith? That is, how can I do so persuasively? Can my views even be translated to something that would hold the attention of an MTD millennial?

My gut instinct has been simply to proceed with an abundance of love. I reached out to my sister recently to remind her of my love for her, regardless of her choices, as well as my hope that, even when we disagree, she would be willing to defend those choices. This has, rather fortuitously, opened up an opportunity for genuine dialogue between us on these topics.

I’ve been racking my brain (and prayer rope), searching for the right way to frame things, but have yet to settle on anything. Any thoughts/advice you or your readers could offer would be greatly appreciated. And while it will be helpful for me, personally, I think it is also of general importance to all Christians, as my question is essentially, “How do we evangelize millennials?”

Thoughts? The problem here — well, a problem here — is that MTD allows for just about anything goes on sexual ethics, and that is absolutely not what normative historical Christianity teaches.

(Non-Christians, if you only want to troll, please withhold your commentary, or I will do it for you.)