These are dark times.

Thirteen pipe bombs were sent to two former presidents and other political and cultural leaders.

In Kentucky, a white man shot and killed two elderly African-Americans at random in a Kroger grocery store after failing to force his way into a black church.

In Pittsburgh, a gunman walked into the Tree of Life synagogue and massacred 11 during Sabbath services in what is believed to be the deadliest attack on the Jewish community in U.S. history.

What time is it? In Isaiah 21: 11-12, a watchman in his tower is asked, “Watchman, what from the night?” The inquiry comes from an occupier and oppressor of the Israelites. The watchman replies, “The morning cometh, and also the night.” What time is it? Is it dusk moving toward midnight, or dawn moving to the day?

We are not bystanders in this drama. It will not be an act of nature that decides, nor a matter of fate. What is clear is that seeds of violence have been strewn across this country. Hatreds that lay fallow have been roused. Divisions have been sharpened. Rain comes from the top, never bottom up.

The president rouses fears of an invasion of an alien caravan coming this way. He invents the claim that terrorists have infiltrated the caravan. He lies that Democrats are to blame for not fixing our laws, although he torpedoed a bipartisan reform bill. He ignores the fact that these are people seeking asylum and will gain entry only after their applications are reviewed and accepted.

His appeals to fear are echoed and augmented by allies for partisan purpose. Their cynicism is clear.

“It doesn’t matter if it’s 100 percent accurate. This is the play,” an administration official told the Daily Beast. Furious, the murderer in Pittsburgh, who raged about a Jewish humanitarian group that helps resettle immigrants in America, arms himself with an assault rifle and three handguns and assaults the synagogue. The president says the answer is to arm synagogues and churches and schools.

Sowing division is not an accident; it is a strategy.

Former President Obama was attacked as illegitimate with the lie about his birth certificate. Neo-Nazi rioters in Charlottesville, chanting “Jews will not replace us,” were praised as including some “fine people.” The American media has been assailed as “the true enemy of the people,” the claim of “fake news” used to discredit reporting on the inventions and lies of the president. Political opponents are slandered before mass audiences. What former President Teddy Roosevelt called the “bully pulpit” — meaning wonderful pulpit — has been taken over by a bully. What time is it?

The seeds of anger and hate are blowing in the wind. No wall, no boundary, no law can contain them. What we do know, as the Bible teaches, is that we will reap what we sow. In this darkness, are we moving toward midnight or toward the dawn? We can decide. The arc of the universe, Dr. Martin Luther King Jr. taught, is long but it moves toward justice, but only if we bend it that way.

This is the test of leadership. It is now that leaders must appeal to the better angels of our nature. It is now that leaders must bring us together and remind us of our common bonds. Clearly as president, Mr. Trump has neither the intention nor the capacity to do that. He has profited from division and has no reason to change course. This is a time for others to lead, for citizens to act to bring us together.

Captive in Egypt, Israelis were asked to make brick without straw, a cruel impossibility. Under slavery and segregation, black people were asked to embrace democracy without the vote, a cruel impossibility.

Now, however, we can vote. We can speak. We can act. We can choose to build walls or to build bridges with our voices, our votes and our marching feet. Today we feel the darkness, the hard cold of hatred and division.

Will we be a thermometer and simply record this environment or act like a thermostat and alter these conditions? Will we choose to descend further toward midnight, or choose to force the dawn? Ultimately, we will decide, by what we do and what we choose not to do, by how we vote or whether we choose not to vote, by whether we come together or whether we allow our fears to drive us apart.

The writer is founder and president of the national Rainbow PUSH Coalition.