The phrase that the antichrist "will act and speak in the name of the beloved and say 'I am God'" is the same warnings of Jesus. He said "I have come in My Father's name and you do not receive Me; if another comes in his own name, him you will receive" John 5:43.
The statement that the antichrist "will set up his image before him in every city" shows that the writer was familiar with Revelation 13:14, which declares that satan will deceive "those who dwell on the earth to make an image to the beast wounded by the sword and lived."