A father has the following obligations toward his son: to circumcise him; to redeem him, if he is a firstborn; to teach him Torah; to find him a wife; and to teach him a craft or a trade. And there are some who say that he must also teach him how to swim. (Talmud Kiddushin 29a)

Reading my Facebook feed on Mother’s Day, I noticed something strange. A number of my gay and straight friends who have posted endlessly about their support for gay marriage wrote moving paeans to their mothers. I imagine many of the same people plan to tribute their fathers this weekend.

But you can’t have both Father’s Day and same-sex marriage. It doesn’t make sense.

Fundamental to the argument for man-woman marriage is that mothers and fathers are essentially different, and both are necessary for the well-being of children. (Of course, divorce and widowhood lead to children not being raised by both parents, but we shouldn’t make social policy out of tragedies.)

Judaism agrees that mothers and fathers have different responsibilities and roles in the raising of children. In addition to the Talmudic text cited above, halacha (Jewish law) holds that religion is passed through the mother, but Cohen and Levi status is passed through the father. We cite a man’s father’s name when calling him to the Torah, but when we pray for the health of any Jew, we mention his or her mother’s name. The idea that mothers and fathers are interchangeable is simply foreign to our tradition.

I think many supporters of gay marriage – Jewish and non-Jewish – know deep down that children need both Moms and Dads, but their political enthusiasm for gay rights keeps them from supporting the institution society has created to bond children to their mothers and fathers.

Here are three examples of this dissonance:

• The gay community flocked to see the stage and film versions of the musical Mamma Mia!, a show whose message is that a woman’s need for her father cannot be filled by her mother alone.

• Last month, an episode of the hyper-gay-positive show Glee was directed by the openly gay actor Chris Colfer, who plays the character Kurt (himself engaged to another man). The epsode centered on the importance of having a relationship with one’s mother before it’s too late.

• Liberals of all stripes have praised President Barack Obama’s book Dreams from My Father, which illustrates the pain a child can suffer when denied access to a parent of one sex. Anyone who thinks that all President Obama needed was a second mother didn’t understand his book.

So what’s the problem with Father’s Day?

We take one day a year to honor our male parents. Part of the role of a father is to teach boys how to be men, and how to relate to women. Another role is to teach girls how to relate to men. One doesn’t have to subscribe to strict gender roles to see the benefits a child gets from having a male actively involved in parenting. As Paul Raeburn’s new book Do Fathers Matter? (Farrar, Straus and Giroux) demonstrates, an increasing amount of quality research shows the essential role of fathers in child development.

Do supporters of same-sex marriage think it’s time we switch to “Parent One Day” and “Parent Two Day”?

I fear that’s the direction society is headed. Because regarding gay marriage, perfectly sensible people who understand the separate and irreplaceable impacts their fathers and mothers have had on them trip up over GayThink’s insistence on Equality, thus ignoring the harms we cause future generations by abandoning traditional marriage.

Sure, encourage gays to adopt – as long as no anti-discrimination laws block an adoption agency from giving even a tiebreaker advantage to an equally qualified opposite-sex couple. Such laws have caused some traditionalist agencies to stop arranging adoptions altogether and hurt many children in the process.

But even gay adoption should be in the context of a society that supports motherhood and fatherhood as fundamentally different and equally necessary institutions.

Too many Jewish leaders, including a few Orthodox ones, have supported both gay marriage and the incompatible notion that Father’s Day reflects key Jewish values.

For example, Orthodox Rabbi Brad Hirschfield, president of the Center for Jewish Learning and Leadership wrote an essay for New York’s Jewish Week entitled “Father’s Day – It’s a Mitzvah,” yet told the Washington Post that “the only real arguments against gay marriage are purely theological in nature.”

If the secular case that kids need both Moms and Dads is not a “real argument,” why does Rabbi Hirschfield care so much about a day specifically for fathers?

Traditional-marriage supporters should take advantage of a Sunday in June (and a Sunday in May) during which average Americans are already thinking about the unique contributions each of their parents made. It’s a perfect opportunity for us to drive home our message. On Mother’s Day and Father’s Day 2015, let’s run television commercials and newspaper advertisements attesting to the importance of both mothers and fathers in our lives.

LGBT people have made much of “coming out” being a sharp strategy to get people to change their minds on gay marriage. I think traditionalists should start “Who’s Your Momma?” and “Who’s Your Daddy?” conversations with our friends and acquaintances in an attempt to win back some same-sex marriage supporters on an issue that is still volatile.

Our strategies so far don’t seem to be changing many minds; maybe this one will.

Follow David Benkof on Facebook or E-mail him at DavidBenkof@gmail.com.