What Happened to Love Thy Neighbor?

I am so upset that I am nauseated.  Another mass murder has happened, and, yet another seems to have been foiled.  For the record, I am heterosexual.  However, I have strong friendships with other women, as well as men, and I don't mind hugging them, holding hands, or giving them a kiss on the cheek in public.  I think my folks raised me to be, and wanted me to be, open-minded regarding anyone's sex, or choice of partner(s).  I believe that each person is what their own unique circumstances in growing up, and development, make them.  I have no right to judge another person's life or lifestyle.  I am NOT them; I have not lived their life; I am not God; I have no right to decide what is right or wrong for them.
  As a human being in America, I make decisions almost every minute of my life.  They are my own personal decisions and I am the person I am today because of all of my past decisions.  I am grieving for the world as a whole today - between the seemingly inevitable choice of the Republicans to support Donald Trump as their candidate at the coming Convention, and between the decisions that two men made,possibly yesterday, possibly today that can help to continue the hatred in our world.
  Around 2 a.m. this morning, a 29-year-old man made a phone call to 911, making reference to the two brothers of the Boston Marathon bombing atrocity, as well as pledging his allegiance to the Islamic State.  The young man was American-born and raised, and was trained as a security guard.  He lived in Fort Pierce, Florida, and he had been interviewed by the FBI in both 2013 and 2014 for possibly having ties to terrorism.  The FBI came away empty-handed and the young man was removed from the watch lists.
   The man went into the Pulse, a lesbian, gay, bisexual, transgender nightclub, after his 911 call.  He was armed with an assault rifle and a Glock pistol.  He began firing when he entered the door of the nightclub.  Some people were able to escape through the bar area and out the back door.  The man had chased people outside, and was continuing to fire his weapons at the clients when police arrived.  The gunman ran back into the building and a stand-off ensued for three hours; then an armored vehicle was crashed into the building to allow engress. The gunman was killed.  But the death toll is currently 50, with 53 wounded.  This happened in Orlando, Orange County, Florida.  One of the policemen who arrived on scene was shot in the face by the gunman; luckily, the Kevlar helmet stopped the bullet and prevented death, but the police officer might lose his eye.
   What the heck happened?  The gunman's father said his son was extremely upset to see two men kissing one another.  How can an expression of love set off such an ugly, violent torrent of hate?
   Then, today, in Santa Monica, California another young man was reported for acting oddly in a neighborhood.  He was going around, pounding on doors at an early hour of the morning.  He was stopped and questioned, and told officers that he was looking for a friend, and that they were going to the Los Angeles Gay Pride event.  The officers checked the man's car and found rifles, including an assault rifle, ammunition and explosives. That man is in custody.

    What happened to "Love thy neighbor?"