"THE EVIL THAT MEN DO

lives after them...." And, I believe that one of the most evil practices among men [humans] is beheading.  I don't remember too many sermons or Sunday School lessons on the subject, but in Matthew 14, we read:

But when Herod’s birthday came, the daughter of Herodias danced before the company and pleased Herod, so that he promised with an oath to give her whatever she might ask.  Prompted by her mother, she said, “Give me the head of John the Baptist here on a platter.”  And the king was sorry, but because of his oaths and his guests he commanded it to be given.  He sent and had John beheaded in the prison, and his head was brought on a platter and given to the girl, and she brought it to her mother.

My earliest visual remembrance of beheading is seared into my mind, probably during the 1950's - I believe that I saw it in Life Magazine.
The story, as told here, is as follows: Sergeant Leonard Siffleet was a commando fighting with the Australian Army in New Guinea when he was captured by natives, who turned him over to the occupying Japanese army. Trained as a radio operator in the Special Forces, Siffleet was part of a secret surveillance detachment sent to New Guinea to watch the coast and report back on enemy activities. After they were turned over to the Japanese, they were held for about two weeks, tortured, and then – on October 24, 1943, on the orders of Vice-Admiral Michiaki Kamada of the Imperial Japanese Navy – Siffleet was executed by beheading. He was beheaded by a Japanese officer, Yasuno Chikao. Chikao ordered another soldier to photograph him while he performed the execution. U.S. forces later recovered the photograph from the body of a Japanese major, in April 1944. Though the Japanese often executed prisoners by beheading (see Toshiaki Mukai and Tsuyoshi Noda above), this is the only known surviving photograph documenting the beheading of a prisoner. I will not even give any links or references to the current Daesh beheadings - such atrocities are barbaric, monstrous, reprehensible [add any adjectives you want] evil.