The synagogue is a place of intimate communion with God, where we strive to understand God's ultimate perfection and the meaning of our world.

Today that sanctity was desecrated, as Jews – in the Holy City of Jerusalem, immersed in morning prayers, adorned in tallit and tefillin – were slaughtered in cold blood by jihadists.

Dozens of worshipers were in the Har Nof synagogue at 7 a.m. when the terrorists struck with guns and axes, leaving the synagogue floor drenched with blood.

This attack hits extremely close to home, as the synagogue attacked was where many Aish staff and alumni pray every morning.

Aish HaTorah's Director of Administration, Rabbi Daniel Schloss, was 10 seconds away from entering the building when he heard shots and saw the wounded running out.

The 12-year-old grandson of Rebbetzin Tzippora Heller, a contributing writer to Aish.com, escaped through a hail of bullets. The boy’s father, Shmulik Goldstein, is hospitalized in critical condition.

Four rabbis murdered – one British and three Americans – who pursued their dream of moving to Israel and raising a Jewish family:

Rabbi Moshe Twersky,  U.S. citizen and scion of a prominent rabbinic family, father of 5, was mentor to Aish senior lecturer Rabbi Gav Friedman and the director of Aish DC , Rabbi Shlomo Buxbaum.

Rabbi Kalman Levine, a native of Kansas City and beloved father of 9, was a teacher of Rabbi Nachman Elsant of the Aish Intermediate Program.

Rabbi Aryeh Kopinsky, American citizen born in Rhode Island and father of 5, whose son studies with my own son-in-law in Bnei Brak.

Rabbi Avraham Shmuel Goldberg, a British citizen and father of 6, including Ms. Libby Goldberg who worked for the Aish Finance Department.

Responding police officer Zidan Sayif, a 27-year-old Israeli Druze, was also killed by the terrorists.

We mourn this grossly horrific act of inhumanity that leaves four widows and 24 orphans on one street.

Holy War

Perhaps it should not surprise us that terrorists struck our holy place – given that the entire focus of this battle has become Jerusalem and the Temple Mount – the Jews' most holy site.

Forget the fact that the inaugural PLO charter from the 1960s never once mentions Jerusalem, and that it only became a jihadist hotspot once the Jews reunited the Holy City.

Jihadists realize that Jerusalem – holy to the Jews for 2,000 years before Islam ever existed – is where the big battle is now taking place.

That is why Islamists complained that Aish HaTorah's rooftop panorama overlooking the Western Wall includes a scale model of the Second Holy Temple. It is this very aspect of Aish's mission – to educate people about the Jewish connection to Jerusalem – that so undercuts the Islamist's false revisionist version of history.

It is what PR legend Charley Levine, buried one day earlier in Jerusalem, called "Jerusalem Denial Syndrome."

Anyone who doesn't recognize that jihadists are fighting a "holy war," has yet to recognize the true root of this conflict.

Incitement and Tolerance

Israel is amidst a Mideast powder keg. Iran is charging toward the nuclear goal line. Egypt, Syria, Lebanon, ISIS and Gaza are among what Ken Abramowitz calls the 10 existential threats to Israel today.

Palestinian leaders are contributing to the problem, having repeatedly celebrated terror and inflamed incitement against Israel. Last week, on official Palestinian Authority TV, officials praised recent terrorists for heeding the call that "Jerusalem needs blood to purify itself of Jews."

Even in the wake of this horrific synagogue massacre, official PA television showed images of Bethlehem residents handing out candy in support of the attack, and the official Fatah website praised the attack as a "heroic operation."

Living in Israel for 20 years, I have seen the barbaric crossing of many red lines, including:

• The incessant rockets and terror at bus stops and cafes.

• The Second Intifada, where friends were murdered by suicide bombers, and bullets whizzed by my house.

• The murder of yeshiva boys studying at Mercaz HaRav, the Fogel family slaughtered in bed, and the kidnapping-murder of three teenage boys this summer.

• Recent wars with Hamas and Hezbollah, which sent virtually every Israeli resident scrambling to bomb shelters.

Today, as mass murder stormed a synagogue in the middle of morning prayers, another red line has been crossed.

Our hearts wrench at the horror of this attack.

Each of us must ask: How does this tragedy challenge me to improve my own life?

Our love and concern goes out to the victims and their families.

We pray for the recovery of those wounded.

And we pray that soon, our land will be blessed with peace.