Mark Barden is advocacy director of Sandy Hook Promise. David Wheeler is a volunteer for the organization. Their sons Daniel Barden, 7, and Benjamin Wheeler, 6, were among the victims of the Dec. 14, 2012, shootings at Sandy Hook Elementary School.

This is the second Father’s Day we will have spent without our sons Daniel and Ben, who were murdered a year and a half ago at Sandy Hook Elementary School in Newtown, Conn. But unlike last Father’s Day, when we grieved quietly, passing the day in solemn remembrance with our families and surviving children, this Father’s Day we feel compelled to speak out.

What has changed since the Sandy Hook shooting? There have been 74 more school shootings, according to the group Everytown for Gun Safety, which tracks news of firearms being discharged at schools as a result of assaults, homicides, suicides and accidental firings. Seventy-four, including tragedies such as those just this month in Seattle and Troutdale, Ore. How could that number not make you outraged? Incensed? Incredulous? How is it that after our beautiful sons were murdered, along with 18 of their classmates and six brave adults, we have seen no major federal policy passed to address this problem? Why is it that we now see summer not as a time of celebration and vacation but as a relief from having to read about new school shootings because kids are no longer at school or on campus?

And now so many school shootings later, with so many families facing the same agony and pain we face this Father’s Day, we have to ask a question.

In a first-of-its-kind live Tumblr forum last week, President Obama expressed his frustration that we as a nation have not been able to make more progress on reducing gun violence by keeping guns out of the hands of those who choose to inflict “unbelievable damage.” The president recalled seeing the face of Richard Martinez, who lost his son last month in the mass shooting near the University of California at Santa Barbara, and said, “As a father myself, I just could not understand the pain he must be going through.” He spoke about the “primal scream that he [Martinez] gave out. Why aren’t we doing something about this?”

A woman puts a photo of a child on a makeshift memorial in the Sandy Hook village of Newtown, Conn., as the town mourns victims killed in a school shooting. (Julio Cortez/AP)

We understand that pain all too well. But before Dec. 14, 2012, we didn’t think it could happen to us, despite seeing reports of other gun violence and hanging our heads in this same disbelief. Richard Martinez didn’t think it would happen to him. The families who lost loved ones to the shootings since Santa Barbara didn’t think it would happen to them. They now join the terrible club of parents who have lost children to gun violence, a club that grows by thousands every year.

Our question is the same: Why aren’t we doing something about this?

We know that Father’s Day is meant to be a day when fathers sit back on their couches, watch sports and take it easy. But this Father’s Day, we ask you to do one thing differently. Look at your children, your beautiful, growing, pesky children who bring you so much joy and sometimes cause you so much heartache, and ask yourself — really ask yourself — this: Am I doing everything I can to keep them safe? Because the answer to that question, if we all answer honestly, clearly is no.

We believe we have reached the tipping point, but it is up to all of us — people of good faith and conscience — to make our voices known. There is wide popular support for the common-sense solutions that we know can make a difference, from comprehensive mental-health reform and expanded background checks to better gun safety solutions. But only a small, vocal minority speaks out beyond the polls.

Since the shooting that took our children, we have been working with Sandy Hook Promise to advance common-sense legislation that could prevent incidences of gun violence and educate Americans on the causes of gun violence — with a focus on mental wellness, community connectedness and gun safety. We do this because it gives us hope. We do this to honor the children we’ve lost, and those who survive, because we believe that fathers inspired to work together can overcome their political differences and sweep away this sense of powerlessness.

So this Father’s Day, do one thing you didn’t do last Father’s Day that will ensure the safety and protection of your children. Join us at Sandy Hook Promise, join another group working for this cause or take action on your own. Send one postcard, one e-mail, one text. And then go hug your kids a little tighter and cherish every moment you have with them.