After the 1st seal of Rev. 6:1 is opened, we see a white horse with a rider who had a bow, and a crown is given unto him.  He then went forth conquering and to conquer. 

I think this depicts the Antichrist who is given authority for 1,260 days or 42 months which is symbolized by him being given a crown.  How does he go forth to peaceably conquer?  He does it through spiritual warfare by promising not to kill those who worship him and his image. The mark of the beast in the right hand or in the forehead in order to buy and sell is a symbol of their loyalty to him and the covenant he made with them not to physically kill them.  It is religious deception because taking the Antichrist's mark in the forehead or in their right hand is going to spiritually kill them eternally and mark them as his own forever.  So the Antichrist only peaceably makes a covenant with those who will worship him and his image.

Daniel 8:25 also says, "..by peace he will destroy many."  Taking his mark is going to destroy their souls for eternity.